Final California 2026 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 2 - San Francisco Bay Region

Water Body Name:	Arroyo Mocho
Water Body ID:	CAR2043008020010905115519
Water Body Type:	River & Stream

DECISION ID	141765	Region 2
Arroyo Mocho

Pollutant:	Temperature, water
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.2 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. 39 lines of evidence are available in the administrative record to assess this pollutant. 22 of the 64 samples exceed the evaluation guideline for COLD and 29 of the 51 samples exceed the evaluation guideline for MIGR beneficial use. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 22 of 64 samples exceeded the evaluation guideline and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho
LOE ID:	298853
Pollutant:	Temperature, water
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Not Recorded
Beneficial Use:	Fish Migration
Number of Samples:	2
Nu Final California 2026 Integrated Report (303(d) List/305(b) Report) Supporting Information Regional Board 2 - San Francisco Bay Region Water Body Name: Arroyo Mocho Water Body ID: CAR2043008020010905115519 Water Body Type: River & Stream   DECISION ID 141765 Region 2      Arroyo Mocho   Pollutant: Temperature, water Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2018) Revision Status Revised Sources: A Source Unknown TMDL Priority: Low Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: This pollutant is being considered for removal from the CWA section 303(d) List under section 4.2 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. 39 lines of evidence are available in the administrative record to assess this pollutant. 22 of the 64 samples exceed the evaluation guideline for COLD and 29 of the 51 samples exceed the evaluation guideline for MIGR beneficial use. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 22 of 64 samples exceeded the evaluation guideline and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.   Listing Extent:     Number of Exceedances: Pollutant: 33%">Guideline Reference: Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298853   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298906   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 2 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298906   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 2 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-02 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298891   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-02 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298891   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 299042   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP  Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 299042   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298924   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 6 Number of Exceedances: 5   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 5 of 6 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not > Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298924   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 6 Number of Exceedances: 5   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 5 of 6 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298754   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298754   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298763   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 2 Number of Exceedances: 2   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 2 of 2 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout.Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298763   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 2 Number of Exceedances: 2   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 2 of 2 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298632   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298632   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd). Temporal Representation: The samples were collected between the dates of 2019-04-30 and 2019-04-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298538   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 12 Number of Exceedances: 10   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 10 of 12 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd). Temporal Representation: The samples were collected between the dates of 2019-04-30 and 2019-04-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298538   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 12 Number of Exceedances: 10   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 10 of 12 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-08-26 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298760   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature " width="33%">Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-08-26 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298760   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298779   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forSummary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298779   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 299006   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 5 Number of Exceedances: 2   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 2 of 5 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (estry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 299006   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 5 Number of Exceedances: 2   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 2 of 5 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-07-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298513   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-07-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298513   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298995   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-03 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298995   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-03 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298931   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 4 Number of Exceedances: 2   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 2 of 4 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-05-30 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298931   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 4 Number of Exceedances: 2   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 2 of 4 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-05-30 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 299014   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 7 Number of Exceedances: 5   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 5 of 7 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 299014   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 7 Number of Exceedances: 5   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 5 of 7 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298959   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   Region 2      Arroyo Mocho   LOE ID: 298959   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298960   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298951   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water LOE ID: 298960   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 298951   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 4789   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat Aquatic Life Use: Wildlife Habitat   Number of Samples: Fraction: Not Recorded   Beneficial Use: Fish Migration   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5 degrees F (2.8 degrees C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Scientific literature reviewed by the Washington Department of Ecology and U.S. EPA indicates that stream temperatures higher than 21C are associated with avoidance behavior and migration blockages in steelhead trout. Guideline Reference: EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B-03-002. Region 10 Office of Water, Seattle, WA Guideline Reference: U.S. Environmental Protection Agency (USEPA). 2001. Issue Paper 1: Salmonid Behavior and Water Temperature Prepared as Part of EPA Region 10 Temperature Water Quality Criteria Guidance Development Project. Region 10, Seattle, WA. EPA-910-D-01-001 May 2001. Guideline Reference: Washington State Department of Ecology (WDOE). 2002. Evaluating Standards for Protecting Aquatic Life in Washington’s Surface Water Quality Standards: Temperature Criteria. Draft Discussion Paper and Literature Summary. Publication Number 00-10-070. Guideline Reference: Beschta RL, Bilby RE, Brown GW, Holtby LB, Hofstra TD. 1987. Stream temperature and aquatic habitat: Fisheries and forestry interactions. In: Salo EO, Cundy TW, eds. Streamside management: forestry and fishery interactions. College of Forest Resources, University of Washington, Seattle. Contribution No. 57. Proceedings of a Symposium held at University of Washington, February 12-14, 1986, pp. 191-231.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 4789   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat Aquatic Life Use: Wildlife Habitat   Number of Samples: 12 Number of Exceedances: 6   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Comprehensive water quality assessment was conducted at the Arroyo Mocho watershed as part of SWAMP assessment. Continuous field monitoring at 15 minute increments of temperature, dissolved oxygen, pH and specific conductance was conducted to determine temporal variability in basic water quality at five locations throughout the watershed. The measured temperatures ranged from 6.1°C to 27.72 °C and varied with season and location. The 17 °C criterion for steelhead was exceeded in 6 out of 12 deployments. High water temperatures exceeding 24 °C, that is a maximum short exposure temperature for survival of salmonids (EPA 1977) were also measured at three monitoring locations at lower and upper reaches of the Creek during spring and summer seasons. At the monitoring site in the lower reach of the Arroyo Mocho Creek high temperature persisted for up to 5.75 hours during spring while at the middle and upper reach it lasted from 5 to more than 9 hours. Data Reference: Water Quality Monitoring and Bioassessment in Nine San Francisco Bay Region Watersheds: Walker Creek, Lagunitas Creek, San Leandro Creek, Wildcat Creek/San Pablo Creek, Suisun Creek, Arroyo Las Positas, Pescadero Creek/Butano Creek, San Gregorio Creek, and Stevens Creek/Permanente Creek. Oakland, CA: Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for enclosed bays and estuaries are specified in the "Water Quality Control Plan for Control of Temperature in the Coastal and Interstate Waters and Enclosed Bays of California" including any revisions to the plan. In addition, the following temperature objectives apply to surface waters: The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sullivan et al. (2000) reviewed a wide range of studies incorporating information from laboratory-based research, field observations, and risk assessment approaches and developed criteria for assessing temperature risk to aquatic life. The 7-day mean temperature (maximum value of the 7-day moving average of the daily mean temperature) of 14.8°C was established as the upper threshold criterion for coho salmon and 17.0°C for steelhead trout. The risk assessment approach used by Sullivan et al. (2000) suggests that temperatures exceeding the above thresholds will cause 10% reduction in average fish growth compared to optimal conditions. Guideline Reference: An Analysis of the Effects of Temperature on Salmonids of the Pacific Northwest with Implications for Selecting Temperature Criteria   Spatial Representation: Temperature was measured at five sites located on the mainstem of Arroyo Mocho Creek. The highest temperatures were recorded at the monitoring location southeast of Livermore in August 2004. High temperatures also occurred in the lower reach of the Creek during the spring season of 2004. Temporal Representation: In 2004 and 2005 the SWAMP Program performed continuous monitoring of temperature at 15 minute intervals for periods of 1-2 weeks in each of three different seasons: winter (5 sites), spring (5 sites), and summer dry season (2 sites). Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 288744   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 7 12 Number of Exceedances: 6   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Comprehensive water quality assessment was conducted at the Arroyo Mocho watershed as part of SWAMP assessment. Continuous field monitoring at 15 minute increments of temperature, dissolved oxygen, pH and specific conductance was conducted to determine temporal variability in basic water quality at five locations throughout the watershed. The measured temperatures ranged from 6.1°C to 27.72 °C and varied with season and location. The 17 °C criterion for steelhead was exceeded in 6 out of 12 deployments. High water temperatures exceeding 24 °C, that is a maximum short exposure temperature for survival of salmonids (EPA 1977) were also measured at three monitoring locations at lower and upper reaches of the Creek during spring and summer seasons. At the monitoring site in the lower reach of the Arroyo Mocho Creek high temperature persisted for up to 5.75 hours during spring while at the middle and upper reach it lasted from 5 to more than 9 hours. Data Reference: Water Quality Monitoring and Bioassessment in Nine San Francisco Bay Region Watersheds: Walker Creek, Lagunitas Creek, San Leandro Creek, Wildcat Creek/San Pablo Creek, Suisun Creek, Arroyo Las Positas, Pescadero Creek/Butano Creek, San Gregorio Creek, and Stevens Creek/Permanente Creek. Oakland, CA: Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for enclosed bays and estuaries are specified in the "Water Quality Control Plan for Control of Temperature in the Coastal and Interstate Waters and Enclosed Bays of California" including any revisions to the plan. In addition, the following temperature objectives apply to surface waters: The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sullivan et al. (2000) reviewed a wide range of studies incorporating information from laboratory-based research, field observations, and risk assessment approaches and developed criteria for assessing temperature risk to aquatic life. The 7-day mean temperature (maximum value of the 7-day moving average of the daily mean temperature) of 14.8°C was established as the upper threshold criterion for coho salmon and 17.0°C for steelhead trout. The risk assessment approach used by Sullivan et al. (2000) suggests that temperatures exceeding the above thresholds will cause 10% reduction in average fish growth compared to optimal conditions. Guideline Reference: An Analysis of the Effects of Temperature on Salmonids of the Pacific Northwest with Implications for Selecting Temperature Criteria   Spatial Representation: Temperature was measured at five sites located on the mainstem of Arroyo Mocho Creek. The highest temperatures were recorded at the monitoring location southeast of Livermore in August 2004. High temperatures also occurred in the lower reach of the Creek during the spring season of 2004. Temporal Representation: In 2004 and 2005 the SWAMP Program performed continuous monitoring of temperature at 15 minute intervals for periods of 1-2 weeks in each of three different seasons: winter (5 sites), spring (5 sites), and summer dry season (2 sites). Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 288744   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 7 Number of Exceedances: 5   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 5 of 7 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 288894   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: 5   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 5 of 7 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 288894   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 288983   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 288983   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 289090   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effectth="67%">Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 289090   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd). Temporal Representation: The samples were collected between the dates of 2019-04-30 and 2019-04-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 289059   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): Spatial Representation: The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd). Temporal Representation: The samples were collected between the dates of 2019-04-30 and 2019-04-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 289059   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 288680   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 288680   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 289007   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 288817   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess th="67%">289007   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 288817   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 289106   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfactWater Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 289106   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 289021   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 289021   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 289107   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 12 Number of Exceedances: 3   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 3 of 12 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Re="left" valign="top" width="67%">Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 289107   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 12 Number of Exceedances: 3   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 3 of 12 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-08-26 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 288444   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 6 Number of Exceedances: 5   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 5 of 6 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt frpresentation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-08-26 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 288444   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 6 Number of Exceedances: 5   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 5 of 6 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 288256   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-03 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 289214     Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 288256   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-03 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 289214   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 288811   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 288811   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 288806   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altd align="left" valign="top" width="33%">Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 288806   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 289157   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 6 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 289157   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 6 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-07-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 288451   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-07-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 288451   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-02 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho   LOE ID: 289003   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 4 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 4 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-05-30 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)).
Temporal Representation:	The samples were collected between the dates of 2019-04-02 and 2019-04-24
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141765, Temperature, water Region 2      Arroyo Mocho
LOE ID:	289003
Pollutant:	Temperature, water
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Not Recorded
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 4 samples exceeded the water quality threshold for Temperature.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.”
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C.
Guideline Reference:	Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C
Guideline Reference:	Inland Fishes of California
Guideline Reference:	Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-05-30
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

DECISION ID	141745	Region 2
Arroyo Mocho

Pollutant:	Diazinon
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)(2018)
Revision Status	Revised
Sources:	Urban Runoff/Storm Sewers
TMDL Name:	San Francisco Bay Urban Creeks Diazinon
TMDL Project Code:	9
Date TMDL Approved by USEPA:	05/21/2007
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed. The USEPA final decision on the 2006 303(d) list was to move this listing to the being addressed by a USEPA approved TMDL portion of the 303(d) list, because the San Francisco Bay Urban Creeks Diazinon TMDL was approved by USEPA on 5/16/07 (USEPA, 2007).
Regional Board Decision Recommendation:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current. The decision has not changed.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:	For 2006, diazinon was moved by USEPA from the 303(d) list to this being addressed list because of a completed USEPA approved TMDL.

Line of Evidence (LOE) for Decision ID 141745, Diazinon Region 2      Arroyo Mocho
LOE ID:	1798
Pollutant:	Diazinon
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	0
Number of Exceedances:	0
Data and Information Type:	Not Specified
Data Used to Assess Water Quality:	Unspecified---This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference:	Placeholder reference 2006 303(d)
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:
Objective/Criterion Reference:
Evaluation Guideline:
Guideline Reference:
Spatial Representation:
Temporal Representation:
DECISION ID	141745	Region 2
Arroyo Mocho

Pollutant:	Diazinon
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)(2018)
Revision Status	Revised
Sources:	Urban Runoff/Storm Sewers
TMDL Name:	San Francisco Bay Urban Creeks Diazinon
TMDL Project Code:	9
Date TMDL Approved by USEPA:	05/21/2007
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed. The USEPA final decision on the 2006 303(d) list was to move this listing to the being addressed by a USEPA approved TMDL portion of the 303(d) list, because the San Francisco Bay Urban Creeks Diazinon TMDL was approved by USEPA on 5/16/07 (USEPA, 2007).
Regional Board Decision Recommendation:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current. The decision has not changed.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:	For 2006, diazinon was moved by USEPA from the 303(d) list to this being addressed list because of a completed USEPA approved TMDL.

Line of Evidence (LOE) for Decision ID 141745, Diazinon Region 2      Arroyo Mocho
LOE ID:	1798
Pollutant:	Diazinon
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	0
Number of Exceedances:	0
Data and Information Type:	Not Specified
Data Used to Assess Water Quality:	Unspecified---This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference:	Placeholder reference 2006 303(d)
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:
Objective/Criterion Reference:
Evaluation Guideline:
Guideline Reference:
Spatial Representation:
Temporal Representation:
Environmental Conditions:
QAPP Information:	QA Info Missing
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 141745, Diazinon Region 2      Arroyo Mocho
LOE ID:	290069
Pollutant:	Diazinon
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for PCBs, Chlorpyrifos, Dacthal, diazinon, disulfoton, endosulfan, Lindane/gamma Hexachlorocyclohexane (gamma-HCH), methyl parathion, thiobencarb.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.Diazinon water quality objective, 0.1 ug/L (acute)
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	PCBs - 0.014 ug/L freshwater continuous Concentration; Chlorpyrifos - 0.015 ug/L (chronic); Dacthal (DCPA) - 14300 ug/L (acute); Disulfoton (Disyston) - 0.05 ug/L (acute); Endosulfan - 0.056 ug/L (chronic)/0.22 ug/L (acute); HCH, gamma-(gamma BHC, Lindane) - 0.95 ug/L (acute); methyl parathion - 0.08 ug/L (acute); Thiobencarb - 3.1 ug/L (acute).
Guideline Reference:	National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed.
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

> Environmental Conditions: QAPP Information: QA Info Missing QAPP Information Reference(s):  

Line of Evidence (LOE) for Decision ID 141745, Diazinon	Region 2
Arroyo Mocho

  LOE ID: 290069   Pollutant: Diazinon LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for PCBs, Chlorpyrifos, Dacthal, diazinon, disulfoton, endosulfan, Lindane/gamma Hexachlorocyclohexane (gamma-HCH), methyl parathion, thiobencarb. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.Diazinon water quality objective, 0.1 ug/L (acute) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: PCBs - 0.014 ug/L freshwater continuous Concentration; Chlorpyrifos - 0.015 ug/L (chronic); Dacthal (DCPA) - 14300 ug/L (acute); Disulfoton (Disyston) - 0.05 ug/L (acute); Endosulfan - 0.056 ug/L (chronic)/0.22 ug/L (acute); HCH, gamma-(gamma BHC, Lindane) - 0.95 ug/L (acute); methyl parathion - 0.08 ug/L (acute); Thiobencarb - 3.1 ug/L (acute). Guideline Reference: National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA   Spatial Representation: Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed. Temporal Representation: Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)  

DECISION ID	141773	Region 2
Arroyo Mocho

Pollutant:	Alkalinity as CaCO3
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for conventional or other pollutants (Table 3.2 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho
LOE ID:	276950
Pollutant:	Alkalinity as CaCO3
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Alkalinity as CaCO3.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2019-06-05
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho
LOE ID:	277010
Pollutant:	Alkalinity as CaCO3
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Alkalinity as CaCO3.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-05-15
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
top" width="67%">Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2. Line of Evidence (LOE) for De   DECISION ID 141773 Region 2      Arroyo Mocho   Pollutant: Alkalinity as CaCO3 Final Listing Decision: Do Not List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: New Decision Revision Status Revised Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for conventional or other pollutants (Table 3.2 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.   Listing Extent:     Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276950   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) cision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277186   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-06-04 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276654   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277010   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-05-15 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277186   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-06-04 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276654   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276949   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-06-04 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277234   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277026   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat     SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276949   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-06-04 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277234   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277026   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276948   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276657   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276948   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life inONT-WEIGHT: bold; PADDING-BOTTOM: 3px; WIDTH: 100%; text-align: left; PADDING-TOP: 3px; font-smooth: always">Arroyo Mocho   LOE ID: 276929   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277027   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Qual freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276657   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276929   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277027   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-05-07 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276967   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276969   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-05-07 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277062   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 4 Number oity Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-05-07 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276967   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276969   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-05-07 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277062   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 4 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-06-13 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276653   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-06-13 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276653   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277028   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277028   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277045   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 4 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-06-13 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276968   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San="left" valign="top" width="33%">LOE ID: 277045   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 4 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-06-13 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276968   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276970   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276970   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277006   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277007   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to A Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277006   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277007   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-02 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277193   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-02 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277193   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276655   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276966   Pollutant: Alkalinity as CaCO3 Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276655   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276966   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277060   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277060   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-02 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277446   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-02 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277446   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277061   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-03 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277394   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality thr; FONT-WEIGHT: bold; PADDING-BOTTOM: 3px; WIDTH: 100%; text-align: left; PADDING-TOP: 3px; font-smooth: always">Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277061   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-03 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277394   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277327   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 aneshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277327   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277029   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 277220   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-03 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho   LOE ID: 276947   Pollutant: Alkalinity as CaCO3 LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Alkalinity as CaCO3. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-05-15 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   d 2015-05-20
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho
LOE ID:	277029
Pollutant:	Alkalinity as CaCO3
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Alkalinity as CaCO3.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-04-23
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho
LOE ID:	277220
Pollutant:	Alkalinity as CaCO3
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-04-03
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141773, Alkalinity as CaCO3 Region 2      Arroyo Mocho
LOE ID:	276947
Pollutant:	Alkalinity as CaCO3
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Alkalinity as CaCO3.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-05-15
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

DECISION ID	151625	Region 2
Arroyo Mocho

Pollutant:	Aluminum
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	During 2024 cycle, the 1988 National Recommended Water Quality Criteria used to assess aluminum data was replaced with U.S. EPA’s 2018 Final Recommended Aquatic Life Criteria for Aluminum in Freshwater. This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. 4 lines of evidence are available in the administrative record to assess this pollutant. 0 of 2 samples exceed the evaluation guideline for the aquatic life beneficial use. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 0 samples exceeded the evaluation guidelines, and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
Listing Extent:

Line of Evidence (LOE) for Decision ID 151625, Aluminum Region 2      Arroyo Mocho
LOE ID:	307217
Pollutant:	Aluminum
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Aluminum.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality   DECISION ID 151625 Region 2      Arroyo Mocho   Pollutant: Aluminum Final Listing Decision: Do Not List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: New Decision Revision Status Revised Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: During 2024 cycle, the 1988 National Recommended Water Quality Criteria used to assess aluminum data was replaced with U.S. EPA’s 2018 Final Recommended Aquatic Life Criteria for Aluminum in Freshwater. This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. 4 lines of evidence are available in the administrative record to assess this pollutant. 0 of 2 samples exceed the evaluation guideline for the aquatic life beneficial use. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 0 samples exceeded the evaluation guidelines, and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.   Listing Extent:     Line of Evidence (LOE) for Decision ID 151625, Aluminum Region 2      Arroyo Mocho   LOE ID: 307217   Pollutant: Aluminum LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Aluminum. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The aluminum criterion for the protection of aquatic life, is pH, total hardness, and dissolved organic carbon (DOC) dependent. When total hardness or DOC data were not available, default values based on the level III ecoregions developed by U.S EPA were substituted (EPA, 2018). When pH data were not available, the median pH value for the ecoregion, a pH value from a comparable waterbody, or a pH value from a local study in the same waterbody was used as a comparable surrogate. Guideline Reference: Final Aquatic Life Ambient Water Quality Criteria for Aluminum. EPA-822-R-18-001. Washington, D.C.: Office of Water, USEPA.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2018-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 151625, Aluminum Region 2      Arroyo Mocho   LOE ID: 307177   Pollutant: Aluminum LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Aluminum. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The aluminum criterion for the protection of aquatic life, is pH, total hardness, and dissolved organic carbon (DOC) dependent. When total hardness or DOC data were not available, default values based on the level III ecoregions developed by U.S EPA were substituted (EPA, 2018). When pH data were not available, the median pH value for the ecoregion, a pH value from a comparable waterbody, or a pH value from a local study in the same waterbody was used as a comparable surrogate. Guideline Reference: Final Aquatic Life Ambient Water Quality Criteria for Aluminum. EPA-822-R-18-001. Washington, D.C.: Office of Water, USEPA.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2018-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 151625, Aluminum Region 2      Arroyo Mocho   LOE ID: 307180   Pollutant: Aluminum LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Aluminum. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The aluminum criterion for the protection of aquatic life, is pH, total hardness, and dissolved organic carbon (DOC) dependent. When total hardness or DOC data were not available, default values based on the level III ecoregions developed by U.S EPA were substituted (EPA, 2018). When pH data were not available, the median pH value for the ecoregion, a pH value from a comparable waterbody, or a pH value from a local study in the same waterbody was used as a comparable surrogate. Guideline Reference: Final Aquatic Life Ambient Water Quality Criteria for Aluminum. EPA-822-R-18-001. Washington, D.C.: Office of Water, USEPA.   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2018-05-16 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 151625, Aluminum Region 2      Arroyo Mocho   LOE ID: 307175   Pollutant: Aluminum LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Aluminum. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The aluminum criterion for the protection of aquatic life, is pH, total hardness, and dissolved organic carbon (DOC) dependent. When total hardness or DOC data were not available, default values based on the level III ecoregions developed by U.S EPA were substituted (EPA, 2018). When pH data were not available, the median pH value for the ecoregion, a pH value from a comparable waterbody, or a pH value from a local study in the same waterbody was used as a comparable surrogate. Guideline Reference: Final Aquatic Life Ambient Water Quality Criteria for Aluminum. EPA-822-R-18-001. Washington, D.C.: Office of Water, USEPA.   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2018-05-16 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The aluminum criterion for the protection of aquatic life, is pH, total hardness, and dissolved organic carbon (DOC) dependent. When total hardness or DOC data were not available, default values based on the level III ecoregions developed by U.S EPA were substituted (EPA, 2018). When pH data were not available, the median pH value for the ecoregion, a pH value from a comparable waterbody, or a pH value from a local study in the same waterbody was used as a comparable surrogate.
Guideline Reference:	Final Aquatic Life Ambient Water Quality Criteria for Aluminum. EPA-822-R-18-001. Washington, D.C.: Office of Water, USEPA.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 151625, Aluminum Region 2      Arroyo Mocho
LOE ID:	307177
Pollutant:	Aluminum
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Aluminum.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The aluminum criterion for the protection of aquatic life, is pH, total hardness, and dissolved organic carbon (DOC) dependent. When total hardness or DOC data were not available, default values based on the level III ecoregions developed by U.S EPA were substituted (EPA, 2018). When pH data were not available, the median pH value for the ecoregion, a pH value from a comparable waterbody, or a pH value from a local study in the same waterbody was used as a comparable surrogate.
Guideline Reference:	Final Aquatic Life Ambient Water Quality Criteria for Aluminum. EPA-822-R-18-001. Washington, D.C.: Office of Water, USEPA.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 151625, Aluminum Region 2      Arroyo Mocho
LOE ID:	307180
Pollutant:	Aluminum
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Aluminum.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The aluminum criterion for the protection of aquatic life, is pH, total hardness, and dissolved organic carbon (DOC) dependent. When total hardness or DOC data were not available, default values based on the level III ecoregions developed by U.S EPA were substituted (EPA, 2018). When pH data were not available, the median pH value for the ecoregion, a pH value from a comparable waterbody, or a pH value from a local study in the same waterbody was used as a comparable surrogate.
Guideline Reference:	Final Aquatic Life Ambient Water Quality Criteria for Aluminum. EPA-822-R-18-001. Washington, D.C.: Office of Water, USEPA.
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 151625, Aluminum Region 2      Arroyo Mocho
LOE ID:	307175
Pollutant:	Aluminum
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Aluminum.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The aluminum criterion for the protection of aquatic life, is pH, total hardness, and dissolved organic carbon (DOC) dependent. When total hardness or DOC data were not available, default values based on the level III ecoregions developed by U.S EPA were substituted (EPA, 2018). When pH data were not available, the median pH value for the ecoregion, a pH value from a comparable waterbody, or a pH value from a local study in the same waterbody was used as a comparable surrogate.
Guideline Reference:	Final Aquatic Life Ambient Water Quality Criteria for Aluminum. EPA-822-R-18-001. Washington, D.C.: Office of Water, USEPA.
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

DECISION ID	150851	Region 2
Arroyo Mocho

Pollutant:	Ammonia
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. The number of measured exceedances is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicant pollutants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that this water segment-pollutant combination should not be placed on the CWA section 303(d) List. Refer to the lines of evidence in this fact sheet for the data and information, sample counts and exceedances, quality assurance documentation, beneficial uses, and water quality objectives or numeric evaluation guidelines relied upon for this decision.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	279374
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference:
DECISION ID	150851	Region 2
Arroyo Mocho

Pollutant:	Ammonia
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. The number of measured exceedances is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicant pollutants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that this water segment-pollutant combination should not be placed on the CWA section 303(d) List. Refer to the lines of evidence in this fact sheet for the data and information, sample counts and exceedances, quality assurance documentation, beneficial uses, and water quality objectives or numeric evaluation guidelines relied upon for this decision.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	279374
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-04-03
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	280174
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2018-05-14
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	277682
Pollutant:	Nitrogewater_issues/programs/tmdl/records/region_2/2010/ref3754.pdf" >Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-04-03
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	280174
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2018-05-14
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	277682
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)).
Temporal Representation:	The samples were collected between the dates of 2019-04-24 and 2019-04-24
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	278817
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:	LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)).
Temporal Representation:	The samples were collected between the dates of 2019-04-24 and 2019-04-24
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	278817
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.).
Temporal Representation:	The samples were collected between the dates of 2015-05-20 and 2015-05-20
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	277498
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road).
Temporal Representation:	The samples were collected between the dates of 2019-04-24 and 2019-06-26
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	277910
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.).
Temporal Representation:	The samples were collected between the dates of 2015-05-20 and 2015-05-20
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	277498
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road).
Temporal Representation:	The samples were collected between the dates of 2019-04-24 and 2019-06-26
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	277910
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471).
Temporal Representation:	The samples were collected between the dates of 2013-05-22 and 2013-05-22
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	278422
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley).
Temporal Representation:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471).
Temporal Representation:	The samples were collected between the dates of 2013-05-22 and 2013-05-22
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	278422
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-04-03
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	277949
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd).
Temporal Representation:	The samples were collected between the dates of 2019-04-30 and 2019-04-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	278264
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	The samples were collected between the dates of 2019-04-03 and 2019-04-03
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	277949
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd).
Temporal Representation:	The samples were collected between the dates of 2019-04-30 and 2019-04-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	278264
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd).
Temporal Representation:	The samples were collected between the dates of 2019-04-30 and 2019-04-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	277906
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence).
Temporal Representation:	The samples were collected between the dates of 2019-04-23 and 2019-07-23
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were develope%">0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd).
Temporal Representation:	The samples were collected between the dates of 2019-04-30 and 2019-04-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	277906
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence).
Temporal Representation:	The samples were collected between the dates of 2019-04-23 and 2019-07-23
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	277925
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473).
Temporal Representation:	The samples were collected between the dates of 2013-05-09 and 2013-05-09
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	278443
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are asd, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	277925
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473).
Temporal Representation:	The samples were collected between the dates of 2013-05-09 and 2013-05-09
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	278443
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2019-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	277841
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	The samples were collected between the dates of 2012-05-30 and 2012-05-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2019-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	277841
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	The samples were collected between the dates of 2012-05-30 and 2012-05-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	277499
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence).
Temporal Representation:	The samples were collected between the dates of 2019-04-23 and 2019-07-23
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	277901
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicityble border="0" width="100%" cellspacing="0" cellpadding="0">
Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 277499   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-04-23 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 277901   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278516   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   <, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

Line of Evidence (LOE) for Decision ID 150851, Ammonia
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2019-06-05
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	278516
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	The samples were collected between the dates of 2014-05-07 and 2014-05-07
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	278752
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.).
Temporal Representation:	The samples were collected between the dates of 2015-05-20 and 2015-05-20
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	278061
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentratiotd width="25%"> Region 2
Arroyo Mocho

  LOE ID: 278752   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278061   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-24 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278286   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-04-24 and 2019-05-30 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Arroyo Mocho

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Objective/Criterion Reference:		Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)).
Temporal Representation:	The samples were collected between the dates of 2019-04-24 and 2019-04-24
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	278286
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection).
Temporal Representation:	The samples were collected between the dates of 2019-04-24 and 2019-05-30
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	278401
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd).
Temporal Representation:	The samples were collected between the dates of 2017-06-12 and 2017-06-12
Environmental Conditions:
QAPP Information:	EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s):	BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	277903
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2018-05-14
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	278753
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd).
Temporal Representation:	The samples were collected between the dates of 2017-06-12 and 2017-06-12
Environmental Conditions:
QAPP Information:	EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s):	BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho

  LOE ID: 278401   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 277903   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278753   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278459   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-04-23 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278081   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-03 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278489   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278808     LOE ID: 278459   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-04-23 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278081   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-03 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278489   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278808   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278773   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278773   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278358   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278754   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fractt" valign="top" width="67%"> Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278358   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278754   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278750   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278750   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278421   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278418   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances:> The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278421   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278418   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278357   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-04-24 and 2019-06-26 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were de 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278357   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-04-24 and 2019-06-26 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278731   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278082   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Boardveloped, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278731   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278082   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278256   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 4 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt f staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278256   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 4 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278106   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 277884   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 4 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 277656   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-04-24 and 2019-05-30 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	278106
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2018-05-14
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	277884
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2019-07-23
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	277656
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection).
Temporal Representation:	The samples were collected between the dates of 2019-04-24 and 2019-05-30
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	278585
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence).
Temporal Representation:	The samples were collected between the dates of 2019-04-23 and 2019-07-23
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	279770
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd).
Temporal Representation:	The samples were collected between the dates of 2019-06-17 and 2019-06-17
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	279524
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	The samples were collected between the dates of 2012-05-30 and 2012-05-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Region 2      Arroyo Mocho
LOE ID:	278585
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence).
Temporal Representation:	The samples were collected between the dates of 2019-04-23 and 2019-07-23
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	279770
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd).
Temporal Representation:	The samples were collected between the dates of 2019-06-17 and 2019-06-17
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	279524
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	The samples were collected between the dates of 2012-05-30 and 2012-05-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	279908
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd).
Temporal Representation:	The samples were collected between the dates of 2017-06-12 and 2017-06-12
Environmental Conditions:
QAPP Information:	EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s):	BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	280109
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd).
Temporal Representation:	The samples were collected between the dates of 2019-04-30 and 2019-04-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	279349
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd).
Temporal Representation:	The samples were collected between the dates of 2019-06-17 and 2019-06-17
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	279680
Pol>	Arroyo Mocho

  LOE ID: 279908   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 280109   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd). Temporal Representation: The samples were collected between the dates of 2019-04-30 and 2019-04-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279349   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279680   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279007   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-24 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279369   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279590   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279007   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-07-23 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279428   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monit"left" valign="top" width="33%">Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-24 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279369   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279590   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279324   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279251   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-07-23 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279428   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitop" width="67%">0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-05-30 and 2019-05-30 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278833   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279324   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279251   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279194   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd). Temporal Representation: The samples were collected between the dates of 2019-04-30 and 2019-04-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279757   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0op" width="67%">0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-05-30 and 2019-05-30 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278833   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2019-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279654   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.

QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	279194
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd).
Temporal Representation:	The samples were collected between the dates of 2019-04-30 and 2019-04-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	279757
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 00" width="100%" cellspacing="0" cellpadding="0">
Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 280095   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2019-06-05 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278879   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembl of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2019-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279654   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   SWAMP Data:

Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd).
Temporal Representation:	The samples were collected between the dates of 2017-06-12 and 2017-06-12
Environmental Conditions:
QAPP Information:	EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s):	BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	279606
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-04-03
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LO0" width="100%" cellspacing="0" cellpadding="0"> Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	280095
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy).
Temporal Representation:	The samples were collected between the dates of 2019-06-05 and 2019-06-05
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	278879
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assemblE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279525   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279771   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Qualed for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279606   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-03 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOity Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence).
Temporal Representation:	The samples were collected between the dates of 2019-07-23 and 2019-07-23
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	279780
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	The samples were collected between the dates of 2014-05-07 and 2014-05-07
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Region 2      Arroyo Mocho
LOE ID:	279525
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471).
Temporal Representation:	The samples were collected between the dates of 2013-05-22 and 2013-05-22
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	279771
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Qualleft; PADDING-TOP: 3px; font-smooth: always">Arroyo Mocho

  LOE ID: 279804   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2019-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279372   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-07-23 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279780   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Objective/Criterion Reference:		Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2019-07-23 and 2019-07-23
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	279629
Pollutant:	Ammonia (Unionized)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout).
Temporal Representation:	The samples were collected between the dates of 2019-05-09 and 2019-05-09
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 150851, Ammonia Region 2      Arroyo Mocho
LOE ID:	279left; PADDING-TOP: 3px; font-smooth: always">Arroyo Mocho

  LOE ID: 279804   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2019-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279372   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-05-30 and 2019-05-30 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 280136   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan33%">Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2019-07-23 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279629   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279 (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278878   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279630   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-05-30 and 2019-05-30 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 280136   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plann="top" width="33%">Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-06-26 and 2019-06-26 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279880   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Re (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 278878   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279630   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-24 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279682   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-06-26 and 2019-06-26 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279373   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-06-26 and 2019-06-26 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279880   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Re3%">Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-07-23 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279708   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-24 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279682   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-06-26 and 2019-06-26 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279373   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   The samples were collected between the dates of 2019-06-05 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 280090   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-07-23 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279772   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2019-07-23 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279781   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   3%">Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-07-23 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279708   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2019-06-05 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 280090   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-07-23 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279772   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2019-07-23 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 150851, Ammonia	Region 2
Arroyo Mocho

  LOE ID: 279781   Pollutant: Ammonia (Unionized) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

DECISION ID	141732	Region 2
Arroyo Mocho

Pollutant:	Anthracene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141732, Anthracene Region 2      Arroyo Mocho
LOE ID:	269492
Pollutant:	Anthracene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Anthracene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for anthracene is the probable effect concentration (PEC) of 845 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141732, Anthracene Region 2      Arroyo Mocho
LOE ID:	269678
Pollutant:	Anthracene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Anthracene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for anthracene is the probable effect concentration (PEC) of 845 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141732, Anthracene Region 2      Arroyo Mocho
LOE ID:	269700
Pollutant:	Anthracene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Anthracene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for anthracene is the probable effect concentration (PEC) of 845 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141732, Anthracene Region 2      Arroyo Mocho
LOE ID:	269573
Pollutant:	Anthracene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Anthracene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for anthracene is the probable effect concentration (PEC) of 845 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141732, Anthracene Region 2      Arroyo Mocho
LOE ID:	290198
Pollutant:	Anthracene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	141732	Region 2
Arroyo Mocho

Pollutant:	Anthracene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141732, Anthracene Region 2      Arroyo Mocho
LOE ID:	269492
Pollutant:	Anthracene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Anthracene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for anthracene is the probable effect concentration (PEC) of 845 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141732, Anthracene Region 2      Arroyo Mocho
LOE ID:	269678
Pollutant:	Anthracene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Anthracene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for anthracene is the probable effect concentration (PEC) of 845 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141732, Anthracene Region 2      Arroyo Mocho
LOE ID:	269700
Pollutant:	Anthracene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Anthracene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for anthracene is the probable effect concentration (PEC) of 845 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141732, Anthracene Region 2      Arroyo Mocho
LOE ID:	269573
Pollutant:	Anthracene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Anthracene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for anthracene is the probable effect concentration (PEC) of 845 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141732, Anthracene Region 2      Arroyo Mocho
LOE ID:	290198
Pollutant:	Anthracene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	141733	Region 2
Arroyo Mocho

Pollutant:	Arsenic
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141733, Arsenic Region 2      Arroyo Mocho
LOE ID:	269957
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Arsenic .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for arsenic is the probable effect concentration (PEC) of 33 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141733, Arsenic Region 2      Arroyo Mocho
LOE ID:	280217
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Arsenic.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 150 ug/L. The conversion factor used to convert the total fraction criterion for arsenic to dissolved fraction criterion is 1. Therefore all data was considered to be representative of the dissolved fraction. (California Toxics Rule, 2000)
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141733, Arsenic Region 2      Arroyo Mocho
LOE ID:	269604
Pollutant:
DECISION ID	141733	Region 2
Arroyo Mocho

Pollutant:	Arsenic
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141733, Arsenic Region 2      Arroyo Mocho
LOE ID:	269957
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Arsenic .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for arsenic is the probable effect concentration (PEC) of 33 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Arsenic
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Arsenic .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for arsenic is the probable effect concentration (PEC) of 33 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141733, Arsenic Region 2      Arroyo Mocho
LOE ID:	269702
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Arsenic .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141733, Arsenic Region 2      Arroyo Mocho
LOE ID:	280217
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Arsenic.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 150 ug/L. The conversion factor used to convert the total fraction criterion for arsenic to dissolved fraction criterion is 1. Therefore all data was considered to be representative of the dissolved fraction. (California Toxics Rule, 2000)
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141733, Arsenic Region 2      Arroyo Mocho
LOE ID:	269604
Pollutant:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for arsenic is the probable effect concentration (PEC) of 33 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141733, Arsenic Region 2      Arroyo Mocho
LOE ID:	279979
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Arsenic.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 150 ug/L. The conversion factor used to convert the total fraction criterion for arsenic to dissolved fraction criterion is 1. Therefore all data was considered to be representative of the dissolved fraction. (California Toxics Rule, 2000)
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141733, Arsenic Region 2      Arsenic LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Arsenic . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for arsenic is the probable effect concentration (PEC) of 33 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141733, Arsenic Region 2      Arroyo Mocho   LOE ID: 269702   Pollutant: Arsenic LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Arsenic . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Arroyo Mocho
LOE ID:	280420
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Arsenic.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 150 ug/L. The conversion factor used to convert the total fraction criterion for arsenic to dissolved fraction criterion is 1. Therefore all data was considered to be representative of the dissolved fraction. (California Toxics Rule, 2000)
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141733, Arsenic Region 2      Arroyo Mocho
LOE ID:	280192
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Arsenic.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	rams/tmdl/records/region_2/2010/ref3754.pdf" >Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for arsenic is the probable effect concentration (PEC) of 33 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141733, Arsenic Region 2      Arroyo Mocho
LOE ID:	279979
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Arsenic.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 150 ug/L. The conversion factor used to convert the total fraction criterion for arsenic to dissolved fraction criterion is 1. Therefore all data was considered to be representative of the dissolved fraction. (California Toxics Rule, 2000)
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141733, Arsenic Region 2      Arroyo Mocho
LOE ID:	280420
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Arsenic.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 150 ug/L. The conversion factor used to convert the total fraction criterion for arsenic to dissolved fraction criterion is 1. Therefore all data was considered to be representative of the dissolved fraction. (California Toxics Rule, 2000)
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141733, Arsenic Region 2      Arroyo Mocho
LOE ID:	280192
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Arsenic.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 150 ug/L. The conversion factor used to convert the total fraction criterion for arsenic to dissolved fraction criterion is 1. Therefore all data was considered to be representative of the dissolved fraction. (California Toxics Rule, 2000)
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141733, Arsenic Region 2      Arroyo Mocho
LOE ID:	95361
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of arsenic, cadmium, chromium, copper, lead, mercury and zinc in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) arsenic - 33 mg/kg dw; cadmium - 4.98 mg/kg dw; chromium - 111 mg/kg dw; copper - 149 mg/kg dw; lead - 128 mg/kg dw; mercury - 1.06 mg/kg dw; nickel - 48.6 mg/kg dw; zinc - 459 mg/kg dw.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a "watershed integrator" site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:	There were no unusual environmental conditions associated with the sampling.
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141733, Arsenic Region 2      Arroyo Mocho
LOE ID:	95367
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for arsenic, chromium VI, copper, lead, nickel, silver and zinc. Concentrations of total dissolved chromium were well below the objective for chromium VI.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Table 3-4 in the Basin Plan (2007) lists freshwater water quality objectives for toxic pollutants: arsenic- 150 ug/L, chromium VI- 11 ug/L, copper - 9.0 ug/L, lead - 2.5 ug/L; nickel - 52 ug/L, silver-3.4 ug/L and zinc - 120 ug/L.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed (above Vulcan Bridge Zone 7).
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:	There were no unusual environmental conditions associated with the sampling.
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141733, Arsenic Region 2      Arroyo Mocho
LOE ID:	269659
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Arsenic .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for arsenic is the probable effect concentration (PEC) of 33 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 150 ug/L. The conversion factor used to convert the total fraction criterion for arsenic to dissolved fraction criterion is 1. Therefore all data was considered to be representative of the dissolved fraction. (California Toxics Rule, 2000) Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2018-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 141733, Arsenic	Region 2
Arroyo Mocho

  LOE ID: 95361   Pollutant: Arsenic LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of arsenic, cadmium, chromium, copper, lead, mercury and zinc in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) arsenic - 33 mg/kg dw; cadmium - 4.98 mg/kg dw; chromium - 111 mg/kg dw; copper - 149 mg/kg dw; lead - 128 mg/kg dw; mercury - 1.06 mg/kg dw; nickel - 48.6 mg/kg dw; zinc - 459 mg/kg dw. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a "watershed integrator" site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: There were no unusual environmental conditions associated with the sampling. QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)  

Line of Evidence (LOE) for Decision ID 141733, Arsenic	Region 2
Arroyo Mocho

  LOE ID: 95367   Pollutant: Arsenic LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for arsenic, chromium VI, copper, lead, nickel, silver and zinc. Concentrations of total dissolved chromium were well below the objective for chromium VI. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Table 3-4 in the Basin Plan (2007) lists freshwater water quality objectives for toxic pollutants: arsenic- 150 ug/L, chromium VI- 11 ug/L, copper - 9.0 ug/L, lead - 2.5 ug/L; nickel - 52 ug/L, silver-3.4 ug/L and zinc - 120 ug/L. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed (above Vulcan Bridge Zone 7). Temporal Representation: Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005. Environmental Conditions: There were no unusual environmental conditions associated with the sampling. QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)  

Line of Evidence (LOE) for Decision ID 141733, Arsenic	Region 2
Arroyo Mocho

  LOE ID: 269659   Pollutant: Arsenic LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Arsenic . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for arsenic is the probable effect concentration (PEC) of 33 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

DECISION ID	141735	Region 2
Arroyo Mocho

Pollutant:	Benzo(a)anthracene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141735, Benzo(a)anthracene Region 2      Arroyo Mocho
LOE ID:	270107
Pollutant:	Benzo(a)anthracene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Benz(a)anthracene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for benz[a]anthrazene is the probable effect concentration (PEC) of 1050 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of c   DECISION ID 141735 Region 2      Arroyo Mocho   Pollutant: Benzo(a)anthracene Final Listing Decision: Do Not List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: New Decision Revision Status Revised Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.   Listing Extent:     Line of Evidence (LOE) for Decision ID 141735, Benzo(a)anthracene Region 2      Arroyo Mocho   LOE ID: 270107   Pollutant: Benzo(a)anthracene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Benz(a)anthracene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for benz[a]anthrazene is the probable effect concentration (PEC) of 1050 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141735, Benzo(a)anthracene Region 2      Arroyo Mocho   LOE ID: 269930   Pollutant: Benzo(a)anthracene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Benz(a)anthracene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for benz[a]anthrazene is the probable effect concentration (PEC) of 1050 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141735, Benzo(a)anthracene Region 2      Arroyo Mocho   LOE ID: 269867   Pollutant: Bonsensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141735, Benzo(a)anthracene Region 2      Arroyo Mocho   LOE ID: 269930   Pollutant: Benzo(a)anthracene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Benz(a)anthracene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for benz[a]anthrazene is the probable effect concentration (PEC) of 1050 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141735, Benzo(a)anthracene Region 2      Arroyo Mocho   LOE ID: 269867   Pollutant: Benzo(a)anthracene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Benz(a)anthracene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for benz[a]anthrazene is the probable effect concentration (PEC) of 1050 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141735, Benzo(a)anthracene Region 2      Arroyo Mocho   LOE ID: 290199   Pollutant: Benzo(a)anthracene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 141735, Benzo(a)anthracene Region 2      Arroyo Mocho   LOE ID: 269810   Pollutant: Benzo(a)anthracene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Benz(a)anthracene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for benz[a]anthrazene is the probable effect concentration (PEC) of 1050 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   enzo(a)anthracene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Benz(a)anthracene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for benz[a]anthrazene is the probable effect concentration (PEC) of 1050 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141735, Benzo(a)anthracene Region 2      Arroyo Mocho
LOE ID:	290199
Pollutant:	Benzo(a)anthracene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141735, Benzo(a)anthracene Region 2      Arroyo Mocho
LOE ID:	269810
Pollutant:	Benzo(a)anthracene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Benz(a)anthracene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for benz[a]anthrazene is the probable effect concentration (PEC) of 1050 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

DECISION ID	141734	Region 2
Arroyo Mocho

Pollutant:	Benzo(a)pyrene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141734, Benzo(a)pyrene Region 2      Arroyo Mocho
LOE ID:	269815
Pollutant:	Benzo(a)pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Benzo(a)pyrene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for benzo[a]pyrene is the probable effect concentration (PEC) of 1450 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141734, Benzo(a)pyrene Region 2      Arroyo Mocho
LOE ID:	270270
Pollutant:	Benzo(a)pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Benzo(a)pyrene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for benzo[a]pyrene is the probable effect concentration (PEC) of 1450 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141734, Benzo(a)pyrene Region 2      Arroyo Mocho
LOE ID:	270113
Pollutant:	Benzo(a)pyrene
DECISION ID	141734	Region 2
Arroyo Mocho

Pollutant:	Benzo(a)pyrene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141734, Benzo(a)pyrene Region 2      Arroyo Mocho
LOE ID:	269815
Pollutant:	Benzo(a)pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Benzo(a)pyrene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for benzo[a]pyrene is the probable effect concentration (PEC) of 1450 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sedign="left" valign="top" width="33%">LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Benzo(a)pyrene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for benzo[a]pyrene is the probable effect concentration (PEC) of 1450 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141734, Benzo(a)pyrene Region 2      Arroyo Mocho
LOE ID:	290210
Pollutant:	Benzo(a)pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141734, Benzo(a)pyrene Region 2      Arroyo Mocho
LOE ID:	270273
Pollutant:	Benzo(a)pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Benzo(a)pyrene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for benzo[a]pyrene is the probable effect concentration (PEC) of 1450 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

iment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141734, Benzo(a)pyrene	Region 2
Arroyo Mocho

  LOE ID: 270270   Pollutant: Benzo(a)pyrene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Benzo(a)pyrene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for benzo[a]pyrene is the probable effect concentration (PEC) of 1450 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141734, Benzo(a)pyrene	Region 2
Arroyo Mocho

  LOE ID: 270113   Pollutant: Benzo(a)pyrene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Benzo(a)pyrene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for benzo[a]pyrene is the probable effect concentration (PEC) of 1450 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141734, Benzo(a)pyrene	Region 2
Arroyo Mocho

  LOE ID: 290210   Pollutant: Benzo(a)pyrene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)  

Line of Evidence (LOE) for Decision ID 141734, Benzo(a)pyrene	Region 2
Arroyo Mocho

  LOE ID: 270273   Pollutant: Benzo(a)pyrene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Benzo(a)pyrene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for benzo[a]pyrene is the probable effect concentration (PEC) of 1450 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

DECISION ID	141771	Region 2
Arroyo Mocho

Pollutant:	Bifenthrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141771, Bifenthrin Region 2      Arroyo Mocho
LOE ID:	270195
Pollutant:	Bifenthrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Bifenthrin .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for bifenthrin is the median lethal concentration (LC50) of 0.43 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.43 ug/g is the geometric mean of LC50 values for bifenthrin (Amweg et al., 2005 and Amweg and Weston, 2007).
Guideline Reference:
DECISION ID	141771	Region 2
Arroyo Mocho

Pollutant:	Bifenthrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141771, Bifenthrin Region 2      Arroyo Mocho
LOE ID:	270195
Pollutant:	Bifenthrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Bifenthrin .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for bifenthrin is the median lethal concentration (LC50) of 0.43 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.43 ug/g is the geometric mean of LC50 values for bifenthrin (Amweg et al., 2005 and Amweg and Weston, 2007).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Guideline Reference:	Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141771, Bifenthrin Region 2      Arroyo Mocho
LOE ID:	270415
Pollutant:	Bifenthrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Bifenthrin .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for bifenthrin is the median lethal concentration (LC50) of 0.43 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.43 ug/g is the geometric mean of LC50 values for bifenthrin (Amweg et al., 2005 and Amweg and Weston, 2007).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Guideline Reference:	Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141771, Bifenthrin Region 2      Arroyo Mocho
LOE ID:	270162
Pollutant:	Bifenthrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Bifenthrin .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for bifenthrin is the median lethal concentration (LC50) of 0.43 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.43 ug/g is the geometric mean of LC50 values for bifenthrin (Amweg et al., 2005 and Amweg and Weston, 2007).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Guideline Reference:	Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141771, Bifenthrin Region 2      Arroyo Mocho
LOE ID:	270403
Pollutant:	Bifenthrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Bifenthrin .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for bifenthrin is the median lethal concentration (LC50) of 0.43 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.43 ug/g is the geometric mean of LC50 values for bifenthrin (Amweg et al., 2005 and Amweg and Weston, 2007).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Guideline Reference:	Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

://www.waterboards.ca.gov/water_issues/programs/tmdl/records/state_board/2008/ref3311.pdf" >Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5 Guideline Reference: Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141771, Bifenthrin	Region 2
Arroyo Mocho

  LOE ID: 270415   Pollutant: Bifenthrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Bifenthrin . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for bifenthrin is the median lethal concentration (LC50) of 0.43 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.43 ug/g is the geometric mean of LC50 values for bifenthrin (Amweg et al., 2005 and Amweg and Weston, 2007). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5 Guideline Reference: Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141771, Bifenthrin	Region 2
Arroyo Mocho

  LOE ID: 270162   Pollutant: Bifenthrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Bifenthrin . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for bifenthrin is the median lethal concentration (LC50) of 0.43 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.43 ug/g is the geometric mean of LC50 values for bifenthrin (Amweg et al., 2005 and Amweg and Weston, 2007). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5 Guideline Reference: Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141771, Bifenthrin	Region 2
Arroyo Mocho

  LOE ID: 270403   Pollutant: Bifenthrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Bifenthrin . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for bifenthrin is the median lethal concentration (LC50) of 0.43 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.43 ug/g is the geometric mean of LC50 values for bifenthrin (Amweg et al., 2005 and Amweg and Weston, 2007). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5 Guideline Reference: Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

DECISION ID	141736	Region 2
Arroyo Mocho

Pollutant:	Cadmium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141736, Cadmium Region 2      Arroyo Mocho
LOE ID:	270755
Pollutant:	Cadmium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cadmium .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for cadmium is the probable effect concentration (PEC) of 4.98 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:
DECISION ID	141736	Region 2
Arroyo Mocho

Pollutant:	Cadmium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141736, Cadmium Region 2      Arroyo Mocho
LOE ID:	270755
Pollutant:	Cadmium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cadmium .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for cadmium is the probable effect concentration (PEC) of 4.98 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141736, Cadmium Region 2      Arroyo Mocho
LOE ID:	280590
Pollutant:	Cadmium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Cadmium.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved cadmium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 2.2 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141736, Cadmium Region 2      Arroyo Mocho
LOE ID:	270708
Pollutant:	Cadmium
LOE Subgroup:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141736, Cadmium Region 2      Arroyo Mocho
LOE ID:	280590
Pollutant:	Cadmium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Cadmium.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved cadmium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 2.2 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141736, Cadmium Region 2      Arroyo Mocho
LOE ID:	270708
Pollutant:	Cadmium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cadmium .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for cadmium is the probable effect concentration (PEC) of 4.98 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141736, Cadmium Region 2      Arroyo Mocho
LOE ID:	280458
Pollutant:	Cadmium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Cadmium.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved cadmium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 2.2 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of nume="top" width="67%">Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cadmium .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for cadmium is the probable effect concentration (PEC) of 4.98 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141736, Cadmium Region 2      Arroyo Mocho
LOE ID:	280458
Pollutant:	Cadmium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Cadmium.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved cadmium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 2.2 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141736, Cadmium Region 2      Arroyo Mocho
LOE ID:	280631
Pollutant:	Cadmium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Cadmium.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved cadmium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 2.2 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141736, Cadmium Region 2      Arroyo Mocho
LOE ID:
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141736, Cadmium Region 2      Arroyo Mocho
LOE ID:	280631
Pollutant:	Cadmium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Cadmium.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved cadmium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 2.2 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141736, Cadmium Region 2      Arroyo Mocho
LOE ID:	95363
Pollutant:	Cadmium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of arsenic, cadmium, chromium, copper, lead, mercury and zinc in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) arsenic - 33 mg/kg dw; cadmium - 4.98 mg/kg dw; chromium - 111 mg/kg dw; copper - 149 mg/kg dw; lead - 128 mg/kg dw; mercury - 1.06 mg/kg dw; nickel - 48.6 mg/kg dw; zinc - 459 mg/kg dw.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a "watershed integrator" site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:	There were no unusual environmental conditions associated with the sampling.
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141736, Cadmium Region 2      Arroyo Mocho
LOE ID:	280564
Pollutant:	Cadmium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Cadmium.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved cadmium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 2.2 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141736, Cadmium Region 2      Arroyo Mocho
LOE ID:	270707
Pollutant:	Cadmium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cadmium .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for cadmium is the probable effect concentration (PEC) of 4.98 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141736, Cadmium Region 2      Arroyo Mocho
LOE ID:	270500
Pollutant:	Cadmium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cadmium .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for cadmium is the probable effect concentration (PEC) of 4.98 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

n="top" width="67%">95363   Pollutant: Cadmium LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of arsenic, cadmium, chromium, copper, lead, mercury and zinc in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) arsenic - 33 mg/kg dw; cadmium - 4.98 mg/kg dw; chromium - 111 mg/kg dw; copper - 149 mg/kg dw; lead - 128 mg/kg dw; mercury - 1.06 mg/kg dw; nickel - 48.6 mg/kg dw; zinc - 459 mg/kg dw. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a "watershed integrator" site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: There were no unusual environmental conditions associated with the sampling. QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)  

Line of Evidence (LOE) for Decision ID 141736, Cadmium	Region 2
Arroyo Mocho

  LOE ID: 280564   Pollutant: Cadmium LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Cadmium. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The dissolved cadmium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 2.2 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2018-05-16 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 141736, Cadmium	Region 2
Arroyo Mocho

  LOE ID: 270707   Pollutant: Cadmium LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cadmium . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for cadmium is the probable effect concentration (PEC) of 4.98 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141736, Cadmium	Region 2
Arroyo Mocho

  LOE ID: 270500   Pollutant: Cadmium LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cadmium . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for cadmium is the probable effect concentration (PEC) of 4.98 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

DECISION ID	141737	Region 2
Arroyo Mocho

Pollutant:	Chlordane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141737, Chlordane Region 2      Arroyo Mocho
LOE ID:	270954
Pollutant:	Chlordane
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chlordane .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for chlordane is the probable effect concentration (PEC) of 17.6 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines   DECISION ID 141737 Region 2      Arroyo Mocho   Pollutant: Chlordane Final Listing Decision: Do Not List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: New Decision Revision Status Revised Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.   Listing Extent:     Line of Evidence (LOE) for Decision ID 141737, Chlordane Region 2      Arroyo Mocho   LOE ID: 270954   Pollutant: Chlordane LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chlordane . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for chlordane is the probable effect concentration (PEC) of 17.6 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141737, Chlordane Region 2      Arroyo Mocho   LOE ID: 290211   Pollutant: Chlordane LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 141737, Chlordane Region 2      Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141737, Chlordane Region 2      Arroyo Mocho   LOE ID: 290211   Pollutant: Chlordane LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 141737, Chlordane Region 2      Arroyo Mocho   LOE ID: 270948   Pollutant: Chlordane LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chlordane . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for chlordane is the probable effect concentration (PEC) of 17.6 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141737, Chlordane Region 2      Arroyo Mocho   LOE ID: 270966   Pollutant: Chlordane LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chlordane . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for chlordane is the probable effect concentration (PEC) of 17.6 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141737, Chlordane Region 2      Arroyo Mocho   LOE ID: 271027   Pollutant: Chlordane LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chlordane . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for chlordane is the probable effect concentration (PEC) of 17.6 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   background-color:#CCCCCC; PADDING-RIGHT: 2%; PADDING-LEFT: 0%; FONT-WEIGHT: bold; PADDING-BOTTOM: 3px; WIDTH: 100%; text-align: left; PADDING-TOP: 3px; font-smooth: always">Arroyo Mocho
LOE ID:	270948
Pollutant:	Chlordane
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chlordane .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for chlordane is the probable effect concentration (PEC) of 17.6 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141737, Chlordane Region 2      Arroyo Mocho
LOE ID:	270966
Pollutant:	Chlordane
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chlordane .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for chlordane is the probable effect concentration (PEC) of 17.6 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141737, Chlordane Region 2      Arroyo Mocho
LOE ID:	271027
Pollutant:	Chlordane
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chlordane .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for chlordane is the probable effect concentration (PEC) of 17.6 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

DECISION ID	141738	Region 2
Arroyo Mocho

Pollutant:	Chloride
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281629
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:
DECISION ID	141738	Region 2
Arroyo Mocho

Pollutant:	Chloride
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281629
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2019-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281659
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence).
Temporal Representation:	The samples were collected between the dates of 2019-05-15 and 2019-05-15
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
: 3px; WIDTH: 100%; text-align: left; PADDING-TOP: 3px; font-smooth: always">Arroyo Mocho Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho   LOE ID: 281659   Pollutant: Chloride LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-05-15 and 2019-05-15 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho   LOE ID: 281739   Pollutant: Chloride LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-05-15 and 2019-05-15 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho   LOE ID: 281304   Pollutant: Chloride LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP
LOE ID:	281739
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence).
Temporal Representation:	The samples were collected between the dates of 2019-05-15 and 2019-05-15
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281304
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road).
Temporal Representation:	The samples were collected between the dates of 2019-06-04 and 2019-06-04
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281806
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2019-06-05
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road).
Temporal Representation:	The samples were collected between the dates of 2019-06-04 and 2019-06-04
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281806
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2019-06-05
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281645
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2019-06-05
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281840
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281645
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2019-06-05
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281840
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd).
Temporal Representation:	The samples were collected between the dates of 2019-06-17 and 2019-06-17
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	282155
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Qualityn="top" width="67%">1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd).
Temporal Representation:	The samples were collected between the dates of 2019-06-17 and 2019-06-17
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	282155
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	The samples were collected between the dates of 2014-05-07 and 2014-05-07
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281630
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout).
Temporal Representation:	The samples were collected between the dates of 2019-05-09 and 2019-05-09
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281115
&nbs Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	The samples were collected between the dates of 2014-05-07 and 2014-05-07
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281630
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout).
Temporal Representation:	The samples were collected between the dates of 2019-05-09 and 2019-05-09
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281115
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	The samples were collected between the dates of 2012-05-30 and 2012-05-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281151
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	The samples were collected between the dates of 2012-05-30 and 2012-05-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281151
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473).
Temporal Representation:	The samples were collected between the dates of 2013-05-09 and 2013-05-09
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281366
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	The samples were collected between the dates of 2014-05-07 and 2014-05-07
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho   LOE ID: 281366   Pollutant: Chloride LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho   LOE ID: 280744   Pollutant: Chloride LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho   LOE ID: 281307   Pollutant: Chloride LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride. Data Reference: Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	280744
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout).
Temporal Representation:	The samples were collected between the dates of 2019-05-09 and 2019-05-09
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281307
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2018-05-14
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281776
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd).
Temporal Representation:	The samples were collecteign="left" valign="top" width="67%">Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2018-05-14
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281776
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd).
Temporal Representation:	The samples were collected between the dates of 2017-06-12 and 2017-06-12
Environmental Conditions:
QAPP Information:	EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s):	BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281818
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd).
Temporal Representation:	The samples were collected between the dates of 2019-04-30 and 2019-04-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281992
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
&nbd between the dates of 2017-06-12 and 2017-06-12
Environmental Conditions:
QAPP Information:	EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s):	BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281818
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd).
Temporal Representation:	The samples were collected between the dates of 2019-04-30 and 2019-04-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281992
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection).
Temporal Representation:	The samples were collected between the dates of 2019-05-07 and 2019-05-07
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281846
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection).
Temporal Representation:	The samples were collected between the dates of 2019-05-07 and 2019-05-07
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281846
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd).
Temporal Representation:	The samples were collected between the dates of 2019-06-17 and 2019-06-17
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281786
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road).
Temporal Representation:	The samples were collected between the dates of 2019-06-04 and 2019-06-04
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141738, Chloride Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho   LOE ID: 281786   Pollutant: Chloride LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-06-04 and 2019-06-04 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho   LOE ID: 281416   Pollutant: Chloride LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho   LOE ID: 281656   Pollutant: Chloride LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Chloride. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024; PADDING-TOP: 3px; font-smooth: always">Region 2      Arroyo Mocho
LOE ID:	281416
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2018-05-14
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281656
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2019-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	280824
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471).
Temporal Representation:	The samples were collected between the dates of 2013-05-22 and 2013-05-22
Environmental Conditions:
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2019-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	280824
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471).
Temporal Representation:	The samples were collected between the dates of 2013-05-22 and 2013-05-22
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281608
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.).
Temporal Representation:	The samples were collected between the dates of 2015-05-20 and 2015-05-20
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281694
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281608
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.).
Temporal Representation:	The samples were collected between the dates of 2015-05-20 and 2015-05-20
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281694
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471).
Temporal Representation:	The samples were collected between the dates of 2013-05-22 and 2013-05-22
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281491
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Clign="top" width="67%">0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471).
Temporal Representation:	The samples were collected between the dates of 2013-05-22 and 2013-05-22
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281491
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.).
Temporal Representation:	The samples were collected between the dates of 2015-05-20 and 2015-05-20
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281385
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd).
Temporal Representation:	The samples were collected between the dates of 2019-04-30 and 2019-04-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281863
Pollutant:	Chloride
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.).
Temporal Representation:	The samples were collected between the dates of 2015-05-20 and 2015-05-20
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281385
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd).
Temporal Representation:	The samples were collected between the dates of 2019-04-30 and 2019-04-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281863
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	The samples were collected between the dates of 2012-05-30 and 2012-05-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281492
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	The samples were collected between the dates of 2012-05-30 and 2012-05-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	281492
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd).
Temporal Representation:	The samples were collected between the dates of 2017-06-12 and 2017-06-12
Environmental Conditions:
QAPP Information:	EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s):	BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho
LOE ID:	282013
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473).
Temporal Representation:	The samples were collected between the dates of 2013-05-09 and 2013-05-09
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for ssues/programs/tmdl/records/region_2/2010/ref3754.pdf" >Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho   LOE ID: 282013   Pollutant: Chloride LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho   LOE ID: 281114   Pollutant: Chloride LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-05-07 and 2019-05-07 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho   LOE ID: 281501   Pollutant: Chloride LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 2   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 2 of 2 samples exceeded the water quality threshold for Chloride. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-06-13 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141738, Chloride Region 2      Arroyo Mocho   LOE ID: 281657   Pollutant: Chloride LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 2   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 2 of 2 samples exceeded the water quality threshold for Chloride. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-06-13 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Decision ID 141738, Chloride		Region 2
Arroyo Mocho

  LOE ID: 281114   Pollutant: Chloride LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-05-07 and 2019-05-07 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 141738, Chloride	Region 2
Arroyo Mocho

  LOE ID: 281501   Pollutant: Chloride LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 2   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 2 of 2 samples exceeded the water quality threshold for Chloride. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-06-13 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 141738, Chloride	Region 2
Arroyo Mocho

  LOE ID: 281657   Pollutant: Chloride LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 2   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 2 of 2 samples exceeded the water quality threshold for Chloride. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-06-13 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

DECISION ID	141739	Region 2
Arroyo Mocho

Pollutant:	Chlorine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. Although there was a sufficient number of samples to assess total chlorine, this water body was given a use rating of Insufficient Information and a Do Not List decision. First, data were collected with field instruments that do not have the sensitivity to detect low levels of total chlorine to assess the freshwater water quality objectives of 11 ug/L and 19 ug/L. Secondly, most of the data were collected only once for a given site, and the data were not collected with the purpose of assessing chlorine levels in the water body. A more appropriate sampling to determine water quality impacts of chlorine might be conducted for future Integrated Report assessments.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho
LOE ID:	282230
Pollutant:	Chlorine
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/   DECISION ID 141739 Region 2      Arroyo Mocho   Pollutant: Chlorine Final Listing Decision: Do Not List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: New Decision Revision Status Revised Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. Although there was a sufficient number of samples to assess total chlorine, this water body was given a use rating of Insufficient Information and a Do Not List decision. First, data were collected with field instruments that do not have the sensitivity to detect low levels of total chlorine to assess the freshwater water quality objectives of 11 ug/L and 19 ug/L. Secondly, most of the data were collected only once for a given site, and the data were not collected with the purpose of assessing chlorine levels in the water body. A more appropriate sampling to determine water quality impacts of chlorine might be conducted for future Integrated Report assessments.   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.   Listing Extent:     QAPP Information Reference(s):">Guideline Reference: Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282230   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282229   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282229   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282676   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282605   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Rep/div> Region 2      Arroyo Mocho   LOE ID: 282676   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282605   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282308   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282308   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282457   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282821   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282457   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282821   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282692   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282692   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282850   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282790   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficialr> Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282850   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282790   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282449   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282449   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282587   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd). Temporal Representation: The samples were collected between the dates of 2019-04-30 and 2019-04-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282456   National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282587   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd). Temporal Representation: The samples were collected between the dates of 2019-04-30 and 2019-04-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282456   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd). Temporal Representation: The samples were collected between the dates of 2019-04-30 and 2019-04-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282849   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282590   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho   LOE ID: 282774   Pollutant: Chlorine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average). Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan	Pollutant:	Chlorine
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd).
Temporal Representation:	The samples were collected between the dates of 2019-04-30 and 2019-04-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho
LOE ID:	282849
Pollutant:	Chlorine
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual.
Data Reference:	Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.).
Temporal Representation:	The samples were collected between the dates of 2015-05-20 and 2015-05-20
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho
LOE ID:	282590
Pollutant:	Chlorine
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471).
Temporal Representation:	The samples were collected between the dates of 2013-05-22 and 2013-05-22
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141739, Chlorine Region 2      Arroyo Mocho
LOE ID:	282774
Pollutant:	Chlorine
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average).
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	The samples were collected between the dates of 2012-05-30 and 2012-05-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

DECISION ID	141741	Region 2
Arroyo Mocho

Pollutant:	Chlorpyrifos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141741, Chlorpyrifos Region 2      Arroyo Mocho
LOE ID:	290057
Pollutant:	Chlorpyrifos
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for PCBs, Chlorpyrifos, Dacthal, diazinon, disulfoton, endosulfan, Lindane/gamma Hexachlorocyclohexane (gamma-HCH), methyl parathion, thiobencarb.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.Diazinon water quality objective, 0.1 ug/L (acute)
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	PCBs - 0.014 ug/L freshwater continuous Concentration; Chlorpyrifos - 0.015 ug/L (chronic); Dacthal (DCPA) - 14300 ug/L (acute); Disulfoton (Disyston) - 0.05 ug/L (acute); Endosulfan - 0.056 ug/L (chronic)/0.22 ug/L (acute); HCH, gamma-(gamma BHC, Lindane) - 0.95 ug/L (acute); methyl parathion - 0.08 ug/L (acute); Thiobencarb - 3.1 ug/L (acute).
Guideline Reference:	National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed.
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	141741	Region 2
Arroyo Mocho

Pollutant:	Chlorpyrifos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141741, Chlorpyrifos Region 2      Arroyo Mocho
LOE ID:	290057
Pollutant:	Chlorpyrifos
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for PCBs, Chlorpyrifos, Dacthal, diazinon, disulfoton, endosulfan, Lindane/gamma Hexachlorocyclohexane (gamma-HCH), methyl parathion, thiobencarb.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.Diazinon water quality objective, 0.1 ug/L (acute)
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	PCBs - 0.014 ug/L freshwater continuous Concentration; Chlorpyrifos - 0.015 ug/L (chronic); Dacthal (DCPA) - 14300 ug/L (acute); Disulfoton (Disyston) - 0.05 ug/L (acute); Endosulfan - 0.056 ug/L (chronic)/0.22 ug/L (acute); HCH, gamma-(gamma BHC, Lindane) - 0.95 ug/L (acute); methyl parathion - 0.08 ug/L (acute); Thiobencarb - 3.1 ug/L (acute).
Guideline Reference:	National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed.
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	141777	Region 2
Arroyo Mocho

Pollutant:	Chromium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141777, Chromium Region 2      Arroyo Mocho
LOE ID:	95362
Pollutant:	Chromium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of arsenic, cadmium, chromium, copper, lead, mercury and zinc in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) arsenic - 33 mg/kg dw; cadmium - 4.98 mg/kg dw; chromium - 111 mg/kg dw; copper - 149 mg/kg dw; lead - 128 mg/kg dw; mercury - 1.06 mg/kg dw; nickel - 48.6 mg/kg dw; zinc - 459 mg/kg dw.
Guideline Reference:
DECISION ID	141777	Region 2
Arroyo Mocho

Pollutant:	Chromium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141777, Chromium Region 2      Arroyo Mocho
LOE ID:	95362
Pollutant:	Chromium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of arsenic, cadmium, chromium, copper, lead, mercury and zinc in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) arsenic - 33 mg/kg dw; cadmium - 4.98 mg/kg dw; chromium - 111 mg/kg dw; copper - 149 mg/kg dw; lead - 128 mg/kg dw; mercury - 1.06 mg/kg dw; nickel - 48.6 mg/kg dw; zinc - 459 mg/kg dw.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a "watershed integrator" site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:	There were no unusual environmental conditions associated with the sampling.
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141777, Chromium Region 2      Arroyo Mocho
LOE ID:	270999
Pollutant:	Chromium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chromium .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for chromium is the probable effect concentration (PEC) of 111 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141777, Chromium Region 2      Arroyo Mocho
&nb.ca.gov/water_issues/programs/tmdl/records/state_board/2006/ref7.pdf" >Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a "watershed integrator" site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:	There were no unusual environmental conditions associated with the sampling.
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141777, Chromium Region 2      Arroyo Mocho
LOE ID:	270999
Pollutant:	Chromium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chromium .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for chromium is the probable effect concentration (PEC) of 111 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141777, Chromium Region 2      Arroyo Mocho
LOE ID:	283106
Pollutant:	Chromium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chromium.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved chromium (III) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is is hardness dependent as described in Table 1 of paragraph (b)(1). The value calculated when using a default hardness of 100 mg/L is 180 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141777, Chromium Region 2      Arroyo Mocho
LOE ID:	283103
Pollutant:	Chromium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chromium.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved chromium (III) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is is hardness dependent as described in Table 1 of paragraph (b)(1). The value calculated when using a default hardness of 100 mg/L is 180 ug/L (California Toxics Rule, 2000).
LOE ID:	283106
Pollutant:	Chromium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chromium.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved chromium (III) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is is hardness dependent as described in Table 1 of paragraph (b)(1). The value calculated when using a default hardness of 100 mg/L is 180 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141777, Chromium Region 2      Arroyo Mocho
LOE ID:	283103
Pollutant:	Chromium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chromium.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved chromium (III) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is is hardness dependent as described in Table 1 of paragraph (b)(1). The value calculated when using a default hardness of 100 mg/L is 180 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141777, Chromium Region 2      Arroyo Mocho
LOE ID:	270818
Pollutant:	Chromium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chromium .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for chromium is the probable effect concentration (PEC) of 111 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141777, Chromium Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2018-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141777, Chromium Region 2      Arroyo Mocho   LOE ID: 270818   Pollutant: Chromium LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chromium . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for chromium is the probable effect concentration (PEC) of 111 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141777, Chromium Region 2      Arroyo Mocho   LOE ID: 95368   Pollutant: Chromium LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for arsenic, chromium VI, copper, lead, nickel, silver and zinc. Concentrations of total dissolved chromium were well below the objective for chromium VI. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Table 3-4 in the Basin Plan (2007) lists freshwater water quality objectives for toxic pollutants: arsenic- 150 ug/L, chromium VI- 11 ug/L, copper - 9.0 ug/L, lead - 2.5 ug/L; nickel - 52 ug/L, silver-3.4 ug/L and zinc - 120 ug/L. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed (above Vulcan Bridge Zone 7). Temporal Representation: Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005. Environmental Conditions: There were no unusual environmental conditions associated with the sampling. QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 141777, Chromium Region 2      Arroyo Mocho   LOE ID: 283085   Pollutant: Chromium LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chromium. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: NG-TOP: 3px; font-smooth: always">Region 2      Arroyo Mocho
LOE ID:	95368
Pollutant:	Chromium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for arsenic, chromium VI, copper, lead, nickel, silver and zinc. Concentrations of total dissolved chromium were well below the objective for chromium VI.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Table 3-4 in the Basin Plan (2007) lists freshwater water quality objectives for toxic pollutants: arsenic- 150 ug/L, chromium VI- 11 ug/L, copper - 9.0 ug/L, lead - 2.5 ug/L; nickel - 52 ug/L, silver-3.4 ug/L and zinc - 120 ug/L.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed (above Vulcan Bridge Zone 7).
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:	There were no unusual environmental conditions associated with the sampling.
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141777, Chromium Region 2      Arroyo Mocho
LOE ID:	283085
Pollutant:	Chromium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chromium.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved chromium (III) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is is hardness dependent as described in Table 1 of paragraph (b)(1). The value calculated when using a default hardness of 100 mg/L is 180 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141777, Chromium Region 2      Arroyo Mocho
LOE ID:	283404
Pollutant:	Chromium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chromium.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved chromium (III) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is is hardness dependent as described in Table 1 of paragraph (b)(1). The value calculated when using a default hardness of 100 mg/L is 180 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141777, Chromium Region 2      Arroyo Mocho
LOE ID:	271127
Pollutant:	Chromium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chromium .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for chromium is the probable effect concentration (PEC) of 111 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141777, Chromium Region 2      Arroyo Mocho
LOE ID:	270801
Pollutant:	Chromium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chromium .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for chromium is the probable effect concentration (PEC) of 111 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

SWAMP   Water Quality Objective/Criterion: The dissolved chromium (III) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is is hardness dependent as described in Table 1 of paragraph (b)(1). The value calculated when using a default hardness of 100 mg/L is 180 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2018-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 141777, Chromium	Region 2
Arroyo Mocho

  LOE ID: 283404   Pollutant: Chromium LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chromium. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The dissolved chromium (III) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is is hardness dependent as described in Table 1 of paragraph (b)(1). The value calculated when using a default hardness of 100 mg/L is 180 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2018-05-16 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 141777, Chromium	Region 2
Arroyo Mocho

  LOE ID: 271127   Pollutant: Chromium LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chromium . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for chromium is the probable effect concentration (PEC) of 111 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141777, Chromium	Region 2
Arroyo Mocho

  LOE ID: 270801   Pollutant: Chromium LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chromium . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for chromium is the probable effect concentration (PEC) of 111 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

DECISION ID	141742	Region 2
Arroyo Mocho

Pollutant:	Chrysene (C1-C4)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141742, Chrysene (C1-C4) Region 2      Arroyo Mocho
LOE ID:	271296
Pollutant:	Chrysene (C1-C4)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chrysene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for chrysene is the probable effect concentration (PEC) of 1290 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment   DECISION ID 141742 Region 2      Arroyo Mocho   Pollutant: Chrysene (C1-C4) Final Listing Decision: Do Not List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: New Decision Revision Status Revised Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.   Listing Extent:     Line of Evidence (LOE) for Decision ID 141742, Chrysene (C1-C4) Region 2      Arroyo Mocho   LOE ID: 271296   Pollutant: Chrysene (C1-C4) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chrysene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for chrysene is the probable effect concentration (PEC) of 1290 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141742, Chrysene (C1-C4) Region 2      Arroyo Mocho   LOE ID: 271139   Pollutant: Chrysene (C1-C4) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chrysene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for chrysene is the probable effect concentration (PEC) of 1290 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141742, Chrysene (C1-C4) Region 2      Arroyo Mocho   LOE ID: 271394   Pollutant: Chrysene (C1-C4)   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141742, Chrysene (C1-C4) Region 2      Arroyo Mocho   LOE ID: 271139   Pollutant: Chrysene (C1-C4) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chrysene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for chrysene is the probable effect concentration (PEC) of 1290 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141742, Chrysene (C1-C4) Region 2      Arroyo Mocho   LOE ID: 271394   Pollutant: Chrysene (C1-C4) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chrysene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for chrysene is the probable effect concentration (PEC) of 1290 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141742, Chrysene (C1-C4) Region 2      Arroyo Mocho   LOE ID: 290212   Pollutant: Chrysene (C1-C4) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 141742, Chrysene (C1-C4) Region 2      Arroyo Mocho   LOE ID: 271309   Pollutant: Chrysene (C1-C4) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chrysene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for chrysene is the probable effect concentration (PEC) of 1290 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   valign="top" width="33%">LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chrysene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for chrysene is the probable effect concentration (PEC) of 1290 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141742, Chrysene (C1-C4) Region 2      Arroyo Mocho
LOE ID:	290212
Pollutant:	Chrysene (C1-C4)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141742, Chrysene (C1-C4) Region 2      Arroyo Mocho
LOE ID:	271309
Pollutant:	Chrysene (C1-C4)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chrysene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for chrysene is the probable effect concentration (PEC) of 1290 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

DECISION ID	141743	Region 2
Arroyo Mocho

Pollutant:	Copper
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141743, Copper Region 2      Arroyo Mocho
LOE ID:	283348
Pollutant:	Copper
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Copper.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved copper criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 9 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site   DECISION ID 141743 Region 2      Arroyo Mocho   Pollutant: Copper Final Listing Decision: Do Not List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2018) Revision Status Revised Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.   Listing Extent:     Line of Evidence (LOE) for Decision ID 141743, Copper Region 2      Arroyo Mocho   LOE ID: 283348   Pollutant: Copper LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Copper. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The dissolved copper criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 9 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2018-05-16 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141743, Copper Region 2      Arroyo Mocho   LOE ID: 283431   Pollutant: Copper LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Copper. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The dissolved copper criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 9 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2018-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141743, Copper Region 2      Arroyo Mocho   LOE ID: 271280   Pollutant: Copper LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2018-05-16 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141743, Copper Region 2      Arroyo Mocho   LOE ID: 283431   Pollutant: Copper LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Copper. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The dissolved copper criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 9 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2018-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141743, Copper Region 2      Arroyo Mocho   LOE ID: 271280   Pollutant: Copper LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Copper . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for copper is the probable effect concentration (PEC) of 149 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141743, Copper Region 2      Arroyo Mocho   LOE ID: 283346   Pollutant: Copper LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Copper. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The dissolved copper criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 9 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Ref>Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Copper . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for copper is the probable effect concentration (PEC) of 149 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141743, Copper Region 2      Arroyo Mocho   LOE ID: 283346   Pollutant: Copper LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Copper. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The dissolved copper criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 9 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2018-05-16 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141743, Copper Region 2      Arroyo Mocho   LOE ID: 283302   Pollutant: Copper LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Copper. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The dissolved copper criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 9 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2018-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141743, Copper Region 2      Arroyo Mocho   LOE ID: 95369   Pollutant: Copper LOE Subgroup: Pollutant-Water Matrix: Water   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2018-05-16 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141743, Copper Region 2      Arroyo Mocho   LOE ID: 283302   Pollutant: Copper LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Copper. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The dissolved copper criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 9 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2018-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141743, Copper Region 2      Arroyo Mocho   LOE ID: 95369   Pollutant: Copper LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for arsenic, chromium VI, copper, lead, nickel, silver and zinc. Concentrations of total dissolved chromium were well below the objective for chromium VI. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Table 3-4 in the Basin Plan (2007) lists freshwater water quality objectives for toxic pollutants: arsenic- 150 ug/L, chromium VI- 11 ug/L, copper - 9.0 ug/L, lead - 2.5 ug/L; nickel - 52 ug/L, silver-3.4 ug/L and zinc - 120 ug/L. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed (above Vulcan Bridge Zone 7). Temporal Representation: Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005. Environmental Conditions: There were no unusual environmental conditions associated with the sampling. QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 141743, Copper Region 2      Arroyo Mocho   LOE ID: 95364   Pollutant: Copper LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of arsenic, cadmium, chromium, copper, lead, mercury and zinc in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) arsenic - 33 mg/kg dw; cadmium - 4.98 mg/kg dw; chromium - 1td> Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for arsenic, chromium VI, copper, lead, nickel, silver and zinc. Concentrations of total dissolved chromium were well below the objective for chromium VI. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Table 3-4 in the Basin Plan (2007) lists freshwater water quality objectives for toxic pollutants: arsenic- 150 ug/L, chromium VI- 11 ug/L, copper - 9.0 ug/L, lead - 2.5 ug/L; nickel - 52 ug/L, silver-3.4 ug/L and zinc - 120 ug/L. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed (above Vulcan Bridge Zone 7). Temporal Representation: Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005. Environmental Conditions: There were no unusual environmental conditions associated with the sampling. QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 141743, Copper Region 2      Arroyo Mocho   LOE ID: 95364   Pollutant: Copper LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of arsenic, cadmium, chromium, copper, lead, mercury and zinc in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) arsenic - 33 mg/kg dw; cadmium - 4.98 mg/kg dw; chromium - 111 mg/kg dw; copper - 149 mg/kg dw; lead - 128 mg/kg dw; mercury - 1.06 mg/kg dw; nickel - 48.6 mg/kg dw; zinc - 459 mg/kg dw. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a "watershed integrator" site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: There were no unusual environmental conditions associated with the sampling. QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 141743, Copper Region 2      Arroyo Mocho   LOE ID: 271513   Pollutant: Copper LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Copper . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for copper is the probable effect concentration (PEC) of 149 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141743, Copper Region 2      Arroyo Mocho   LOE ID: 271104   Pollutant: Copper LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Copper . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for copper is the probable effect concentration (PEC) of 149 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141743, Copper Region 2      Arroyo Mocho   LOE ID: 271463   Pollutant: Copper LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Copper . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for copper is the probable effect concentration (PEC) of 149 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   11 mg/kg dw; copper - 149 mg/kg dw; lead - 128 mg/kg dw; mercury - 1.06 mg/kg dw; nickel - 48.6 mg/kg dw; zinc - 459 mg/kg dw.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a "watershed integrator" site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:	There were no unusual environmental conditions associated with the sampling.
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141743, Copper Region 2      Arroyo Mocho
LOE ID:	271513
Pollutant:	Copper
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Copper .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for copper is the probable effect concentration (PEC) of 149 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141743, Copper Region 2      Arroyo Mocho
LOE ID:	271104
Pollutant:	Copper
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Copper .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for copper is the probable effect concentration (PEC) of 149 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141743, Copper Region 2      Arroyo Mocho
LOE ID:	271463
Pollutant:	Copper
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Copper .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for copper is the probable effect concentration (PEC) of 149 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

DECISION ID	141774	Region 2
Arroyo Mocho

Pollutant:	Cyfluthrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141774, Cyfluthrin Region 2      Arroyo Mocho
LOE ID:	271787
Pollutant:	Cyfluthrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Cyfluthrin, total .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for cyfluthrin is the median lethal concentration (LC50) of 1.1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.1 ug/g is the geometric mean of LC50 values for cyfluthrin (Amweg et al., 2005).
Guideline Reference:
DECISION ID	141774	Region 2
Arroyo Mocho

Pollutant:	Cyfluthrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141774, Cyfluthrin Region 2      Arroyo Mocho
LOE ID:	271787
Pollutant:	Cyfluthrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Cyfluthrin, total .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for cyfluthrin is the median lethal concentration (LC50) of 1.1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.1 ug/g is the geometric mean of LC50 values for cyfluthrin (Amweg et al., 2005).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141774, Cyfluthrin Region 2      Arroyo Mocho
LOE ID:	272021
Pollutant:	Cyfluthrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cyfluthrin, total .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for cyfluthrin is the median lethal concentration (LC50) of 1.1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.1 ug/g is the geometric mean of LC50 values for cyfluthrin (Amweg et al., 2005).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141774, Cyfluthrin Region 2      Arroyo Mocho
LOE ID:	271940
Pollutant:	Cyfluthrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Cyfluthrin, total .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for cyfluthrin is the median lethal concentration (LC50) of 1.1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.1 ug/g is the geometric mean of LC50 values for cyfluthrin (Amweg et al., 2005).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141774, Cyfluthrin Region 2      Arroyo Mocho
LOE ID:	271986
Pollutant:	Cyfluthrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cyfluthrin, total .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for cyfluthrin is the median lethal concentration (LC50) of 1.1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.1 ug/g is the geometric mean of LC50 values for cyfluthrin (Amweg et al., 2005).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

gov/water_issues/programs/tmdl/records/state_board/2008/ref3311.pdf" >Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141774, Cyfluthrin	Region 2
Arroyo Mocho

  LOE ID: 272021   Pollutant: Cyfluthrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cyfluthrin, total . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for cyfluthrin is the median lethal concentration (LC50) of 1.1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.1 ug/g is the geometric mean of LC50 values for cyfluthrin (Amweg et al., 2005). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141774, Cyfluthrin	Region 2
Arroyo Mocho

  LOE ID: 271940   Pollutant: Cyfluthrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Cyfluthrin, total . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for cyfluthrin is the median lethal concentration (LC50) of 1.1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.1 ug/g is the geometric mean of LC50 values for cyfluthrin (Amweg et al., 2005). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141774, Cyfluthrin	Region 2
Arroyo Mocho

  LOE ID: 271986   Pollutant: Cyfluthrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cyfluthrin, total . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for cyfluthrin is the median lethal concentration (LC50) of 1.1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.1 ug/g is the geometric mean of LC50 values for cyfluthrin (Amweg et al., 2005). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

DECISION ID	141776	Region 2
Arroyo Mocho

Pollutant:	Cyhalothrin, Lambda
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141776, Cyhalothrin, Lambda Region 2      Arroyo Mocho
LOE ID:	271937
Pollutant:	Cyhalothrin, Lambda
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cyhalothrin, Total lambda- .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for lambda-cyhalothrin is the median lethal concentration (LC50) of 0.44 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.44 ug/g is the geometric mean of LC50 values for lambda-cyhalothrin (Amweg et al., 2005).
Guideline Reference:
DECISION ID	141776	Region 2
Arroyo Mocho

Pollutant:	Cyhalothrin, Lambda
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141776, Cyhalothrin, Lambda Region 2      Arroyo Mocho
LOE ID:	271937
Pollutant:	Cyhalothrin, Lambda
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cyhalothrin, Total lambda- .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for lambda-cyhalothrin is the median lethal concentration (LC50) of 0.44 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.44 ug/g is the geometric mean of LC50 values for lambda-cyhalothrin (Amweg et al., 2005).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141776, Cyhalothrin, Lambda Region 2      Arroyo Mocho
LOE ID:	271833
Pollutant:	Cyhalothrin, Lambda
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cyhalothrin, Total lambda- .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for lambda-cyhalothrin is the median lethal concentration (LC50) of 0.44 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.44 ug/g is the geometric mean of LC50 values for lambda-cyhalothrin (Amweg et al., 2005).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141776, Cyhalothrin, Lambda Region 2      Arroyo Mocho
LOE ID:	272008
Pollutant:	Cyhalothrin, Lambda
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cyhalothrin, Total lambda- .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for lambda-cyhalothrin is the median lethal concentration (LC50) of 0.44 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.44 ug/g is the geometric mean of LC50 values for lambda-cyhalothrin (Amweg et al., 2005).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141776, Cyhalothrin, Lambda Region 2      Arroyo Mocho
LOE ID:	271969
Pollutant:	Cyhalothrin, Lambda
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cyhalothrin, Total lambda- .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for lambda-cyhalothrin is the median lethal concentration (LC50) of 0.44 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.44 ug/g is the geometric mean of LC50 values for lambda-cyhalothrin (Amweg et al., 2005).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

"top" width="67%">Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141776, Cyhalothrin, Lambda	Region 2
Arroyo Mocho

  LOE ID: 271833   Pollutant: Cyhalothrin, Lambda LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cyhalothrin, Total lambda- . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for lambda-cyhalothrin is the median lethal concentration (LC50) of 0.44 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.44 ug/g is the geometric mean of LC50 values for lambda-cyhalothrin (Amweg et al., 2005). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141776, Cyhalothrin, Lambda	Region 2
Arroyo Mocho

  LOE ID: 272008   Pollutant: Cyhalothrin, Lambda LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cyhalothrin, Total lambda- . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for lambda-cyhalothrin is the median lethal concentration (LC50) of 0.44 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.44 ug/g is the geometric mean of LC50 values for lambda-cyhalothrin (Amweg et al., 2005). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141776, Cyhalothrin, Lambda	Region 2
Arroyo Mocho

  LOE ID: 271969   Pollutant: Cyhalothrin, Lambda LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cyhalothrin, Total lambda- . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for lambda-cyhalothrin is the median lethal concentration (LC50) of 0.44 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.44 ug/g is the geometric mean of LC50 values for lambda-cyhalothrin (Amweg et al., 2005). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

DECISION ID	141772	Region 2
Arroyo Mocho

Pollutant:	Cypermethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141772, Cypermethrin Region 2      Arroyo Mocho
LOE ID:	271992
Pollutant:	Cypermethrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cypermethrin, Total .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for cypermethrin is the median lethal concentration (LC50) of 0.3 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.3 ug/g is the geometric mean of LC50 values for cypermethrin from Maund et al., (2002).
Guideline Reference:
DECISION ID	141772	Region 2
Arroyo Mocho

Pollutant:	Cypermethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141772, Cypermethrin Region 2      Arroyo Mocho
LOE ID:	271992
Pollutant:	Cypermethrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cypermethrin, Total .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for cypermethrin is the median lethal concentration (LC50) of 0.3 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.3 ug/g is the geometric mean of LC50 values for cypermethrin from Maund et al., (2002).
Guideline Reference:	Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141772, Cypermethrin Region 2      Arroyo Mocho
LOE ID:	272089
Pollutant:	Cypermethrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cypermethrin, Total .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for cypermethrin is the median lethal concentration (LC50) of 0.3 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.3 ug/g is the geometric mean of LC50 values for cypermethrin from Maund et al., (2002).
Guideline Reference:	Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141772, Cypermethrin Region 2      Arroyo Mocho
LOE ID:	272052
Pollutant:	Cypermethrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cypermethrin, Total .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for cypermethrin is the median lethal concentration (LC50) of 0.3 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.3 ug/g is the geometric mean of LC50 values for cypermethrin from Maund et al., (2002).
Guideline Reference:	Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141772, Cypermethrin Region 2      Arroyo Mocho
LOE ID:	272327
Pollutant:	Cypermethrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cypermethrin, Total .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for cypermethrin is the median lethal concentration (LC50) of 0.3 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.3 ug/g is the geometric mean of LC50 values for cypermethrin from Maund et al., (2002).
Guideline Reference:	Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

w.waterboards.ca.gov/water_issues/programs/tmdl/records/state_board/2010/ref3820.pdf" >Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141772, Cypermethrin	Region 2
Arroyo Mocho

  LOE ID: 272089   Pollutant: Cypermethrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cypermethrin, Total . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for cypermethrin is the median lethal concentration (LC50) of 0.3 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.3 ug/g is the geometric mean of LC50 values for cypermethrin from Maund et al., (2002). Guideline Reference: Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141772, Cypermethrin	Region 2
Arroyo Mocho

  LOE ID: 272052   Pollutant: Cypermethrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cypermethrin, Total . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for cypermethrin is the median lethal concentration (LC50) of 0.3 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.3 ug/g is the geometric mean of LC50 values for cypermethrin from Maund et al., (2002). Guideline Reference: Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141772, Cypermethrin	Region 2
Arroyo Mocho

  LOE ID: 272327   Pollutant: Cypermethrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cypermethrin, Total . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for cypermethrin is the median lethal concentration (LC50) of 0.3 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.3 ug/g is the geometric mean of LC50 values for cypermethrin from Maund et al., (2002). Guideline Reference: Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

DECISION ID	145710	Region 2
Arroyo Mocho

Pollutant:	DDD (Dichlorodiphenyldichloroethane)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 145710, DDD (Dichlorodiphenyldichloroethane) Region 2      Arroyo Mocho
LOE ID:	272251
Pollutant:	DDD (Dichlorodiphenyldichloroethane)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDD (Dichlorodiphenyldichloroethane) .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the sum of DDD is the probable effect concentration (PEC) of 28 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:
DECISION ID	145710	Region 2
Arroyo Mocho

Pollutant:	DDD (Dichlorodiphenyldichloroethane)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Line of Evidence (LOE) for Decision ID 145710, DDD (Dichlorodiphenyldichloroethane) Region 2      Arroyo Mocho
LOE ID:	272251
Pollutant:	DDD (Dichlorodiphenyldichloroethane)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDD (Dichlorodiphenyldichloroethane) .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the sum of DDD is the probable effect concentration (PEC) of 28 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 145710, DDD (Dichlorodiphenyldichloroethane) Region 2      Arroyo Mocho
LOE ID:	272215
Pollutant:	DDD (Dichlorodiphenyldichloroethane)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDD (Dichlorodiphenyldichloroethane) .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the sum of DDD is the probable effect concentration (PEC) of 28 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 145710, DDD (Dichlorodiphenyldichloroethane) Region 2      Arroyo Mocho
LOE ID:	289997
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 145710, DDD (Dichlorodiphenyldichloroethane) Region 2      Arroyo Mocho
LOE ID:	272215
Pollutant:	DDD (Dichlorodiphenyldichloroethane)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDD (Dichlorodiphenyldichloroethane) .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the sum of DDD is the probable effect concentration (PEC) of 28 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 145710, DDD (Dichlorodiphenyldichloroethane) Region 2      Arroyo Mocho
LOE ID:	289997
Pollutant:	DDD (Dichlorodiphenyldichloroethane)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 145710, DDD (Dichlorodiphenyldichloroethane) Region 2      Arroyo Mocho
LOE ID:	272100
Pollutant:	DDD (Dichlorodiphenyldichloroethane)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDD (Dichlorodiphenyldichloroethane) .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the sum of DDD is the probable effect concentration (PEC) of 28 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 145710, DDD (Dichlorodiphenyldichloroethane) Region 2      Arroyo Mocho
LOE ID:	272290
Pollutant:	DDD (Dichlorodiphenyldichloroethane)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDD (Dichlorodiphenyldichloroethane) .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the sum of DDD is the probable effect concentration (PEC) of 28 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

/tr>   Pollutant: DDD (Dichlorodiphenyldichloroethane) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)  

Line of Evidence (LOE) for Decision ID 145710, DDD (Dichlorodiphenyldichloroethane)	Region 2
Arroyo Mocho

  LOE ID: 272100   Pollutant: DDD (Dichlorodiphenyldichloroethane) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDD (Dichlorodiphenyldichloroethane) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for the sum of DDD is the probable effect concentration (PEC) of 28 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 145710, DDD (Dichlorodiphenyldichloroethane)	Region 2
Arroyo Mocho

  LOE ID: 272290   Pollutant: DDD (Dichlorodiphenyldichloroethane) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDD (Dichlorodiphenyldichloroethane) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for the sum of DDD is the probable effect concentration (PEC) of 28 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

DECISION ID	148160	Region 2
Arroyo Mocho

Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 148160, DDE (Dichlorodiphenyldichloroethylene) Region 2      Arroyo Mocho
LOE ID:	272299
Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDE (Dichlorodiphenyldichloroethylene) .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the sum of DDE is the probable effect concentration (PEC) of 31.3 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:
DECISION ID	148160	Region 2
Arroyo Mocho

Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 148160, DDE (Dichlorodiphenyldichloroethylene) Region 2      Arroyo Mocho
LOE ID:	272299
Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDE (Dichlorodiphenyldichloroethylene) .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the sum of DDE is the probable effect concentration (PEC) of 31.3 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 148160, DDE (Dichlorodiphenyldichloroethylene) Region 2      Arroyo Mocho
LOE ID:	272284
Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDE (Dichlorodiphenyldichloroethylene) .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the sum of DDE is the probable effect concentration (PEC) of 31.3 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 148160, DDE (Dichlorodiphenyldichloroethylene) Region 2      Arroyo Mocho
LOE ID:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 148160, DDE (Dichlorodiphenyldichloroethylene) Region 2      Arroyo Mocho
LOE ID:	272284
Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDE (Dichlorodiphenyldichloroethylene) .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the sum of DDE is the probable effect concentration (PEC) of 31.3 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 148160, DDE (Dichlorodiphenyldichloroethylene) Region 2      Arroyo Mocho
LOE ID:	272262
Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDE (Dichlorodiphenyldichloroethylene) .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the sum of DDE is the probable effect concentration (PEC) of 31.3 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 148160, DDE (Dichlorodiphenyldichloroethylene) Region 2      Arroyo Mocho
LOE ID:	289998
Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 148160, DDE (Dichlorodiphenyldichloroethylene) Region 2      Arroyo Mocho
LOE ID:	272048
Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDE (Dichlorodiphenyldichloroethylene) .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the sum of DDE is the probable effect concentration (PEC) of 31.3 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

="67%">272262   Pollutant: DDE (Dichlorodiphenyldichloroethylene) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDE (Dichlorodiphenyldichloroethylene) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for the sum of DDE is the probable effect concentration (PEC) of 31.3 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 148160, DDE (Dichlorodiphenyldichloroethylene)	Region 2
Arroyo Mocho

  LOE ID: 289998   Pollutant: DDE (Dichlorodiphenyldichloroethylene) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)  

Line of Evidence (LOE) for Decision ID 148160, DDE (Dichlorodiphenyldichloroethylene)	Region 2
Arroyo Mocho

  LOE ID: 272048   Pollutant: DDE (Dichlorodiphenyldichloroethylene) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDE (Dichlorodiphenyldichloroethylene) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for the sum of DDE is the probable effect concentration (PEC) of 31.3 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

DECISION ID	148243	Region 2
Arroyo Mocho

Pollutant:	DDT (Dichlorodiphenyltrichloroethane)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
Listing Extent:

Line of Evidence (LOE) for Decision ID 148243, DDT (Dichlorodiphenyltrichloroethane) Region 2      Arroyo Mocho
LOE ID:	276134
Pollutant:	Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD) .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for total DDTs is the probable effect concentration (PEC) of 572 ug/kg dry weight (MacDonald et al., 2000   DECISION ID 148243 Region 2      Arroyo Mocho   Pollutant: DDT (Dichlorodiphenyltrichloroethane) Final Listing Decision: Do Not List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: New Decision Revision Status Revised Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.   Listing Extent:     Line of Evidence (LOE) for Decision ID 148243, DDT (Dichlorodiphenyltrichloroethane) Region 2      Arroyo Mocho   LOE ID: 276134   Pollutant: Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for total DDTs is the probable effect concentration (PEC) of 572 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 148243, DDT (Dichlorodiphenyltrichloroethane) Region 2      Arroyo Mocho   LOE ID: 276400   Pollutant: Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for total DDTs is the probable effect concentration (PEC) of 572 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 148243, DDT (Dichlorodiphenyltrichloroethane) Region 2      Arroyo Mocho   LOE ID: 276382   Pollutant: Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for total DDTs is the probable effect concentration (PEC) of 572 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 148243, DDT (Dichlorodiphenyltrichloroethane) Region 2      Arroyo Mocho   LOE ID: 276379   Pollutant: Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 148243, DDT (Dichlorodiphenyltrichloroethane) Region 2      Arroyo Mocho   LOE ID: 276400   Pollutant: Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for total DDTs is the probable effect concentration (PEC) of 572 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 148243, DDT (Dichlorodiphenyltrichloroethane) Region 2      Arroyo Mocho   LOE ID: 276382   Pollutant: Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for total DDTs is the probable effect concentration (PEC) of 572 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 148243, DDT (Dichlorodiphenyltrichloroethane) Region 2      Arroyo Mocho   LOE ID: 276379   Pollutant: Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for total DDTs is the probable effect concentration (PEC) of 572 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 148243, DDT (Dichlorodiphenyltrichloroethane) Region 2      Arroyo Mocho   LOE ID: 272414   Pollutant: DDT (Dichlorodiphenyltrichloroethane) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDT (Dichlorodiphenyltrichloroethane) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for the sum of DDT is the probable effect concentration (PEC) of 62.9 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 148243, DDT (Dichlorodiphenyltrichloroethane) Region 2      Arroyo Mocho   LOE ID: 272547   Pollutant: DDT (Dichlorodiphenyltrichloroethane) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDT (Dichlorodiphenyltrichloroethane) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for the sum of DDT is the probable effect concentration (PEC) of 62.9 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 148243, DDT (Dichlorodiphenyltrichloroethane) Region 2      Arroyo Mocho   LOE ID: 289999   Pollutant: DDT (Dichlorodiphenyltrichloroethane) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for total DDTs is the probable effect concentration (PEC) of 572 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 148243, DDT (Dichlorodiphenyltrichloroethane) Region 2      Arroyo Mocho   LOE ID: 272414   Pollutant: DDT (Dichlorodiphenyltrichloroethane) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDT (Dichlorodiphenyltrichloroethane) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for the sum of DDT is the probable effect concentration (PEC) of 62.9 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 148243, DDT (Dichlorodiphenyltrichloroethane) Region 2      Arroyo Mocho   LOE ID: 272547   Pollutant: DDT (Dichlorodiphenyltrichloroethane) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDT (Dichlorodiphenyltrichloroethane) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for the sum of DDT is the probable effect concentration (PEC) of 62.9 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 148243, DDT (Dichlorodiphenyltrichloroethane) Region 2      Arroyo Mocho   LOE ID: 289999   Pollutant: DDT (Dichlorodiphenyltrichloroethane) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 148243, DDT (Dichlorodiphenyltrichloroethane) Region 2      Arroyo Mocho   LOE ID: 272627   Pollutant: DDT (Dichlorodiphenyltrichloroethane) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDT (Dichlorodiphenyltrichloroethane) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for the sum of DDT is the probable effect concentration (PEC) of 62.9 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 148243, DDT (Dichlorodiphenyltrichloroethane) Region 2      Arroyo Mocho   LOE ID: 272489   Pollutant: DDT (Dichlorodiphenyltrichloroethane) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDT (Dichlorodiphenyltrichloroethane) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for the sum of DDT is the probable effect concentration (PEC) of 62.9 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   "67%">PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 148243, DDT (Dichlorodiphenyltrichloroethane) Region 2      Arroyo Mocho
LOE ID:	272627
Pollutant:	DDT (Dichlorodiphenyltrichloroethane)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDT (Dichlorodiphenyltrichloroethane) .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the sum of DDT is the probable effect concentration (PEC) of 62.9 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 148243, DDT (Dichlorodiphenyltrichloroethane) Region 2      Arroyo Mocho
LOE ID:	272489
Pollutant:	DDT (Dichlorodiphenyltrichloroethane)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDT (Dichlorodiphenyltrichloroethane) .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the sum of DDT is the probable effect concentration (PEC) of 62.9 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

DECISION ID	141744	Region 2
Arroyo Mocho

Pollutant:	Dacthal
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141744, Dacthal Region 2      Arroyo Mocho
LOE ID:	290068
Pollutant:	Dacthal
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for PCBs, Chlorpyrifos, Dacthal, diazinon, disulfoton, endosulfan, Lindane/gamma Hexachlorocyclohexane (gamma-HCH), methyl parathion, thiobencarb.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.Diazinon water quality objective, 0.1 ug/L (acute)
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	PCBs - 0.014 ug/L freshwater continuous Concentration; Chlorpyrifos - 0.015 ug/L (chronic); Dacthal (DCPA) - 14300 ug/L (acute); Disulfoton (Disyston) - 0.05 ug/L (acute); Endosulfan - 0.056 ug/L (chronic)/0.22 ug/L (acute); HCH, gamma-(gamma BHC, Lindane) - 0.95 ug/L (acute); methyl parathion - 0.08 ug/L (acute); Thiobencarb - 3.1 ug/L (acute).
Guideline Reference:	National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed.
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	141744	Region 2
Arroyo Mocho

Pollutant:	Dacthal
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141744, Dacthal Region 2      Arroyo Mocho
LOE ID:	290068
Pollutant:	Dacthal
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for PCBs, Chlorpyrifos, Dacthal, diazinon, disulfoton, endosulfan, Lindane/gamma Hexachlorocyclohexane (gamma-HCH), methyl parathion, thiobencarb.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.Diazinon water quality objective, 0.1 ug/L (acute)
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	PCBs - 0.014 ug/L freshwater continuous Concentration; Chlorpyrifos - 0.015 ug/L (chronic); Dacthal (DCPA) - 14300 ug/L (acute); Disulfoton (Disyston) - 0.05 ug/L (acute); Endosulfan - 0.056 ug/L (chronic)/0.22 ug/L (acute); HCH, gamma-(gamma BHC, Lindane) - 0.95 ug/L (acute); methyl parathion - 0.08 ug/L (acute); Thiobencarb - 3.1 ug/L (acute).
Guideline Reference:	National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed.
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	141775	Region 2
Arroyo Mocho

Pollutant:	Deltamethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141775, Deltamethrin Region 2      Arroyo Mocho
LOE ID:	272375
Pollutant:	Deltamethrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Deltamethrin .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for deltamethrin is the median lethal concentration (LC50) of 0.79 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.79 ug/g is the geometric mean of LC50 values for deltamethrin (Amweg et al., 2005).
Guideline Reference:
DECISION ID	141775	Region 2
Arroyo Mocho

Pollutant:	Deltamethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141775, Deltamethrin Region 2      Arroyo Mocho
LOE ID:	272375
Pollutant:	Deltamethrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Deltamethrin .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for deltamethrin is the median lethal concentration (LC50) of 0.79 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.79 ug/g is the geometric mean of LC50 values for deltamethrin (Amweg et al., 2005).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141775, Deltamethrin Region 2      Arroyo Mocho
LOE ID:	272451
Pollutant:	Deltamethrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Deltamethrin .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for deltamethrin is the median lethal concentration (LC50) of 0.79 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.79 ug/g is the geometric mean of LC50 values for deltamethrin (Amweg et al., 2005).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141775, Deltamethrin Region 2      Arroyo Mocho
LOE ID:	272474
Pollutant:	Deltamethrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Deltamethrin .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for deltamethrin is the median lethal concentration (LC50) of 0.79 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.79 ug/g is the geometric mean of LC50 values for deltamethrin (Amweg et al., 2005).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141775, Deltamethrin Region 2      Arroyo Mocho
LOE ID:	272458
Pollutant:	Deltamethrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Deltamethrin .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for deltamethrin is the median lethal concentration (LC50) of 0.79 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.79 ug/g is the geometric mean of LC50 values for deltamethrin (Amweg et al., 2005).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

rds.ca.gov/water_issues/programs/tmdl/records/state_board/2008/ref3311.pdf" >Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141775, Deltamethrin	Region 2
Arroyo Mocho

  LOE ID: 272451   Pollutant: Deltamethrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Deltamethrin . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for deltamethrin is the median lethal concentration (LC50) of 0.79 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.79 ug/g is the geometric mean of LC50 values for deltamethrin (Amweg et al., 2005). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141775, Deltamethrin	Region 2
Arroyo Mocho

  LOE ID: 272474   Pollutant: Deltamethrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Deltamethrin . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for deltamethrin is the median lethal concentration (LC50) of 0.79 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.79 ug/g is the geometric mean of LC50 values for deltamethrin (Amweg et al., 2005). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141775, Deltamethrin	Region 2
Arroyo Mocho

  LOE ID: 272458   Pollutant: Deltamethrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Deltamethrin . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for deltamethrin is the median lethal concentration (LC50) of 0.79 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.79 ug/g is the geometric mean of LC50 values for deltamethrin (Amweg et al., 2005). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

DECISION ID	141746	Region 2
Arroyo Mocho

Pollutant:	Dieldrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141746, Dieldrin Region 2      Arroyo Mocho
LOE ID:	272823
Pollutant:	Dieldrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Dieldrin .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for dieldrin is the probable effect concentration (PEC) of 61.8 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for f   DECISION ID 141746 Region 2      Arroyo Mocho   Pollutant: Dieldrin Final Listing Decision: Do Not List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: New Decision Revision Status Revised Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.   Listing Extent:     Line of Evidence (LOE) for Decision ID 141746, Dieldrin Region 2      Arroyo Mocho   LOE ID: 272823   Pollutant: Dieldrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Dieldrin . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for dieldrin is the probable effect concentration (PEC) of 61.8 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141746, Dieldrin Region 2      Arroyo Mocho   LOE ID: 272666   Pollutant: Dieldrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Dieldrin . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for dieldrin is the probable effect concentration (PEC) of 61.8 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141746, Dieldrin Region 2      Arroyo Mocho   LOE ID: 272810   Pollutant: Dieldrin LOE Subgroup: Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141746, Dieldrin Region 2      Arroyo Mocho   LOE ID: 272666   Pollutant: Dieldrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Dieldrin . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for dieldrin is the probable effect concentration (PEC) of 61.8 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141746, Dieldrin Region 2      Arroyo Mocho   LOE ID: 272810   Pollutant: Dieldrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Dieldrin . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for dieldrin is the probable effect concentration (PEC) of 61.8 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141746, Dieldrin Region 2      Arroyo Mocho   LOE ID: 272703   Pollutant: Dieldrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Dieldrin . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for dieldrin is the probable effect concentration (PEC) of 61.8 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141746, Dieldrin Region 2      Arroyo Mocho   LOE ID: 290013   Pollutant: Dieldrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   left" valign="top" width="67%">Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Dieldrin .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for dieldrin is the probable effect concentration (PEC) of 61.8 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141746, Dieldrin Region 2      Arroyo Mocho
LOE ID:	272703
Pollutant:	Dieldrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Dieldrin .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for dieldrin is the probable effect concentration (PEC) of 61.8 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141746, Dieldrin Region 2      Arroyo Mocho
LOE ID:	290013
Pollutant:	Dieldrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	141747	Region 2
Arroyo Mocho

Pollutant:	Disulfoton
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141747, Disulfoton Region 2      Arroyo Mocho
LOE ID:	290070
Pollutant:	Disulfoton
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for PCBs, Chlorpyrifos, Dacthal, diazinon, disulfoton, endosulfan, Lindane/gamma Hexachlorocyclohexane (gamma-HCH), methyl parathion, thiobencarb.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.Diazinon water quality objective, 0.1 ug/L (acute)
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	PCBs - 0.014 ug/L freshwater continuous Concentration; Chlorpyrifos - 0.015 ug/L (chronic); Dacthal (DCPA) - 14300 ug/L (acute); Disulfoton (Disyston) - 0.05 ug/L (acute); Endosulfan - 0.056 ug/L (chronic)/0.22 ug/L (acute); HCH, gamma-(gamma BHC, Lindane) - 0.95 ug/L (acute); methyl parathion - 0.08 ug/L (acute); Thiobencarb - 3.1 ug/L (acute).
Guideline Reference:	National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed.
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	141747	Region 2
Arroyo Mocho

Pollutant:	Disulfoton
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141747, Disulfoton Region 2      Arroyo Mocho
LOE ID:	290070
Pollutant:	Disulfoton
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for PCBs, Chlorpyrifos, Dacthal, diazinon, disulfoton, endosulfan, Lindane/gamma Hexachlorocyclohexane (gamma-HCH), methyl parathion, thiobencarb.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.Diazinon water quality objective, 0.1 ug/L (acute)
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	PCBs - 0.014 ug/L freshwater continuous Concentration; Chlorpyrifos - 0.015 ug/L (chronic); Dacthal (DCPA) - 14300 ug/L (acute); Disulfoton (Disyston) - 0.05 ug/L (acute); Endosulfan - 0.056 ug/L (chronic)/0.22 ug/L (acute); HCH, gamma-(gamma BHC, Lindane) - 0.95 ug/L (acute); methyl parathion - 0.08 ug/L (acute); Thiobencarb - 3.1 ug/L (acute).
Guideline Reference:	National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed.
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	141748	Region 2
Arroyo Mocho

Pollutant:	Endosulfan
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141748, Endosulfan Region 2      Arroyo Mocho
LOE ID:	290082
Pollutant:	Endosulfan
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for PCBs, Chlorpyrifos, Dacthal, diazinon, disulfoton, endosulfan, Lindane/gamma Hexachlorocyclohexane (gamma-HCH), methyl parathion, thiobencarb.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.Diazinon water quality objective, 0.1 ug/L (acute)
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	PCBs - 0.014 ug/L freshwater continuous Concentration; Chlorpyrifos - 0.015 ug/L (chronic); Dacthal (DCPA) - 14300 ug/L (acute); Disulfoton (Disyston) - 0.05 ug/L (acute); Endosulfan - 0.056 ug/L (chronic)/0.22 ug/L (acute); HCH, gamma-(gamma BHC, Lindane) - 0.95 ug/L (acute); methyl parathion - 0.08 ug/L (acute); Thiobencarb - 3.1 ug/L (acute).
Guideline Reference:	National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed.
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	141748	Region 2
Arroyo Mocho

Pollutant:	Endosulfan
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141748, Endosulfan Region 2      Arroyo Mocho
LOE ID:	290082
Pollutant:	Endosulfan
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for PCBs, Chlorpyrifos, Dacthal, diazinon, disulfoton, endosulfan, Lindane/gamma Hexachlorocyclohexane (gamma-HCH), methyl parathion, thiobencarb.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.Diazinon water quality objective, 0.1 ug/L (acute)
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	PCBs - 0.014 ug/L freshwater continuous Concentration; Chlorpyrifos - 0.015 ug/L (chronic); Dacthal (DCPA) - 14300 ug/L (acute); Disulfoton (Disyston) - 0.05 ug/L (acute); Endosulfan - 0.056 ug/L (chronic)/0.22 ug/L (acute); HCH, gamma-(gamma BHC, Lindane) - 0.95 ug/L (acute); methyl parathion - 0.08 ug/L (acute); Thiobencarb - 3.1 ug/L (acute).
Guideline Reference:	National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed.
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	141749	Region 2
Arroyo Mocho

Pollutant:	Endrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141749, Endrin Region 2      Arroyo Mocho
LOE ID:	272836
Pollutant:	Endrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Endrin .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for endrin is the probable effect concentration (PEC) of 207 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater e   DECISION ID 141749 Region 2      Arroyo Mocho   Pollutant: Endrin Final Listing Decision: Do Not List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: New Decision Revision Status Revised Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.   Listing Extent:     Line of Evidence (LOE) for Decision ID 141749, Endrin Region 2      Arroyo Mocho   LOE ID: 272836   Pollutant: Endrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Endrin . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for endrin is the probable effect concentration (PEC) of 207 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141749, Endrin Region 2      Arroyo Mocho   LOE ID: 272792   Pollutant: Endrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Endrin . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for endrin is the probable effect concentration (PEC) of 207 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141749, Endrin Region 2      Arroyo Mocho   LOE ID: 290014   Pollutant: Endrin LOE Subgroup:   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141749, Endrin Region 2      Arroyo Mocho   LOE ID: 272792   Pollutant: Endrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Endrin . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for endrin is the probable effect concentration (PEC) of 207 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141749, Endrin Region 2      Arroyo Mocho   LOE ID: 290014   Pollutant: Endrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 141749, Endrin Region 2      Arroyo Mocho   LOE ID: 272895   Pollutant: Endrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Endrin . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for endrin is the probable effect concentration (PEC) of 207 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141749, Endrin Region 2      Arroyo Mocho   LOE ID: 272965   Pollutant: Endrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Endrin . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for endrin is the probable effect concentration (PEC) of 207 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   ="67%">Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141749, Endrin Region 2      Arroyo Mocho
LOE ID:	272895
Pollutant:	Endrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Endrin .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for endrin is the probable effect concentration (PEC) of 207 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141749, Endrin Region 2      Arroyo Mocho
LOE ID:	272965
Pollutant:	Endrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Endrin .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for endrin is the probable effect concentration (PEC) of 207 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

DECISION ID	141778	Region 2
Arroyo Mocho

Pollutant:	Esfenvalerate/Fenvalerate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141778, Esfenvalerate/Fenvalerate Region 2      Arroyo Mocho
LOE ID:	273168
Pollutant:	Esfenvalerate/Fenvalerate
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Esfenvalerate/Fenvalerate, Total .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.5 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.5 ug/g is the geometric mean of LC50 values for esfenvalerate/fenvalerate (Amweg et al., 2005).
Guideline Refe   DECISION ID 141778 Region 2      Arroyo Mocho   Pollutant: Esfenvalerate/Fenvalerate Final Listing Decision: Do Not List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: New Decision Revision Status Revised Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.   Listing Extent:     Line of Evidence (LOE) for Decision ID 141778, Esfenvalerate/Fenvalerate Region 2      Arroyo Mocho   LOE ID: 273168   Pollutant: Esfenvalerate/Fenvalerate LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Esfenvalerate/Fenvalerate, Total . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.5 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.5 ug/g is the geometric mean of LC50 values for esfenvalerate/fenvalerate (Amweg et al., 2005). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141778, Esfenvalerate/Fenvalerate Region 2      Arroyo Mocho   LOE ID: 273029   Pollutant: Esfenvalerate/Fenvalerate LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Esfenvalerate/Fenvalerate, Total . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.5 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.5 ug/g is the geometric mean of LC50 values for esfenvalerate/fenvalerate (Amweg et al., 2005). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141778, Esfenvalerate/Fenvalerate Region 2      Arroyo Mocho   LOE ID: 273237   Pollutant: Esfenvalerate/Fenvalerate LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Esfenvalerate/Fenvalerate, Total . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.5 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.5 ug/g is the geometric mean of LC50 values for esfenvalerate/fenvalerate (Amweg et al., 2005). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141778, Esfenvalerate/Fenvalerate Region 2      Arroyo Mocho   LOE ID: 273030   Pollutant: Esfenvalerate/Fenvalerate LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Esfenvalerate/Fenvalerate, Total . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.5 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.5 ug/g is the geometric mean of LC50 values for esfenvalerate/fenvalerate (Amweg et al., 2005). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   rence:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141778, Esfenvalerate/Fenvalerate Region 2      Arroyo Mocho
LOE ID:	273029
Pollutant:	Esfenvalerate/Fenvalerate
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Esfenvalerate/Fenvalerate, Total .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.5 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.5 ug/g is the geometric mean of LC50 values for esfenvalerate/fenvalerate (Amweg et al., 2005).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141778, Esfenvalerate/Fenvalerate Region 2      Arroyo Mocho
LOE ID:	273237
Pollutant:	Esfenvalerate/Fenvalerate
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Esfenvalerate/Fenvalerate, Total .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.5 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.5 ug/g is the geometric mean of LC50 values for esfenvalerate/fenvalerate (Amweg et al., 2005).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141778, Esfenvalerate/Fenvalerate Region 2      Arroyo Mocho
LOE ID:	273030
Pollutant:	Esfenvalerate/Fenvalerate
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Esfenvalerate/Fenvalerate, Total .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.5 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.5 ug/g is the geometric mean of LC50 values for esfenvalerate/fenvalerate (Amweg et al., 2005).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

DECISION ID	141750	Region 2
Arroyo Mocho

Pollutant:	Fluoranthene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141750, Fluoranthene Region 2      Arroyo Mocho
LOE ID:	273440
Pollutant:	Fluoranthene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fluoranthene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for fluoranthene is the probable effect concentration (PEC) of 2230 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment qual   DECISION ID 141750 Region 2      Arroyo Mocho   Pollutant: Fluoranthene Final Listing Decision: Do Not List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: New Decision Revision Status Revised Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.   Listing Extent:     Line of Evidence (LOE) for Decision ID 141750, Fluoranthene Region 2      Arroyo Mocho   LOE ID: 273440   Pollutant: Fluoranthene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fluoranthene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for fluoranthene is the probable effect concentration (PEC) of 2230 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141750, Fluoranthene Region 2      Arroyo Mocho   LOE ID: 273438   Pollutant: Fluoranthene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fluoranthene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for fluoranthene is the probable effect concentration (PEC) of 2230 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141750, Fluoranthene Region 2      Arroyo Mocho   LOE ID: 273498   Pollutant: Fluoranthene Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141750, Fluoranthene Region 2      Arroyo Mocho   LOE ID: 273438   Pollutant: Fluoranthene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fluoranthene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for fluoranthene is the probable effect concentration (PEC) of 2230 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141750, Fluoranthene Region 2      Arroyo Mocho   LOE ID: 273498   Pollutant: Fluoranthene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fluoranthene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for fluoranthene is the probable effect concentration (PEC) of 2230 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141750, Fluoranthene Region 2      Arroyo Mocho   LOE ID: 273519   Pollutant: Fluoranthene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fluoranthene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for fluoranthene is the probable effect concentration (PEC) of 2230 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141750, Fluoranthene Region 2      Arroyo Mocho   LOE ID: 290015   Pollutant: Fluoranthene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   " width="33%">LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fluoranthene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for fluoranthene is the probable effect concentration (PEC) of 2230 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141750, Fluoranthene Region 2      Arroyo Mocho
LOE ID:	273519
Pollutant:	Fluoranthene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fluoranthene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for fluoranthene is the probable effect concentration (PEC) of 2230 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141750, Fluoranthene Region 2      Arroyo Mocho
LOE ID:	290015
Pollutant:	Fluoranthene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	141751	Region 2
Arroyo Mocho

Pollutant:	Fluorene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141751, Fluorene Region 2      Arroyo Mocho
LOE ID:	290028
Pollutant:	Fluorene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum   DECISION ID 141751 Region 2      Arroyo Mocho   Pollutant: Fluorene Final Listing Decision: Do Not List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: New Decision Revision Status Revised Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.   Listing Extent:     Line of Evidence (LOE) for Decision ID 141751, Fluorene Region 2      Arroyo Mocho   LOE ID: 290028   Pollutant: Fluorene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 141751, Fluorene Region 2      Arroyo Mocho   LOE ID: 273306   Pollutant: Fluorene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fluorene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for fluorene is the probable effect concentration (PEC) for Fluorene is 536 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141751, Fluorene Region 2      Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 141751, Fluorene Region 2      Arroyo Mocho   LOE ID: 273306   Pollutant: Fluorene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fluorene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for fluorene is the probable effect concentration (PEC) for Fluorene is 536 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141751, Fluorene Region 2      Arroyo Mocho   LOE ID: 273423   Pollutant: Fluorene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fluorene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for fluorene is the probable effect concentration (PEC) for Fluorene is 536 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141751, Fluorene Region 2      Arroyo Mocho   LOE ID: 273384   Pollutant: Fluorene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fluorene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for fluorene is the probable effect concentration (PEC) for Fluorene is 536 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141751, Fluorene Region 2      Arroyo Mocho   LOE ID: 273752   Pollutant: Fluorene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fluorene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for fluorene is the probable effect concentration (PEC) for Fluorene is 536 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   le="background-color:#CCCCCC; PADDING-RIGHT: 2%; PADDING-LEFT: 0%; FONT-WEIGHT: bold; PADDING-BOTTOM: 3px; WIDTH: 100%; text-align: left; PADDING-TOP: 3px; font-smooth: always">Arroyo Mocho
LOE ID:	273423
Pollutant:	Fluorene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fluorene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for fluorene is the probable effect concentration (PEC) for Fluorene is 536 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141751, Fluorene Region 2      Arroyo Mocho
LOE ID:	273384
Pollutant:	Fluorene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fluorene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for fluorene is the probable effect concentration (PEC) for Fluorene is 536 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141751, Fluorene Region 2      Arroyo Mocho
LOE ID:	273752
Pollutant:	Fluorene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fluorene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for fluorene is the probable effect concentration (PEC) for Fluorene is 536 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

DECISION ID	141752	Region 2
Arroyo Mocho

Pollutant:	Heptachlor epoxide
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141752, Heptachlor epoxide Region 2      Arroyo Mocho
LOE ID:	290029
Pollutant:	Heptachlor epoxide
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	141752	Region 2
Arroyo Mocho

Pollutant:	Heptachlor epoxide
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141752, Heptachlor epoxide Region 2      Arroyo Mocho
LOE ID:	290029
Pollutant:	Heptachlor epoxide
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	141753	Region 2
Arroyo Mocho

Pollutant:	Lead
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141753, Lead Region 2      Arroyo Mocho
LOE ID:	273749
Pollutant:	Lead
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Lead .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for lead is the probable effect concentration (PEC) of 128 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141753, Lead Region 2      Arroyo Mocho
LOE ID:	284313
Pollutant:	Lead
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Lead.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved lead criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 2.5 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141753, Lead Region 2      Arroyo Mocho
LOE ID:	284178
Pollutant:	Lead
LOE Subgroup:	Pollutant-Water
Matrix:	Water
DECISION ID	141753	Region 2
Arroyo Mocho

Pollutant:	Lead
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

r>

Line of Evidence (LOE) for Decision ID 141753, Lead Region 2      Arroyo Mocho
LOE ID:	273749
Pollutant:	Lead
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Lead .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for lead is the probable effect concentration (PEC) of 128 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141753, Lead Region 2      Arroyo Mocho
LOE ID:	284313
Pollutant:	Lead
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Lead.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved lead criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 2.5 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141753, Lead Region 2      Arroyo Mocho
LOE ID:	284178
Pollutant:	Lead
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Lead.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved lead criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 2.5 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141753, Lead Region 2      Arroyo Mocho
LOE ID:	274032
Pollutant:	Lead
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Lead .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for lead is the probable effect concentration (PEC) of 128 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141753, Lead Region 2      Arroyo Mocho
LOE ID:	274205
Pollutant:	Lead
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Lead .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for lead is the probable effect concentration (PEC) of 128 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141753, Lead Region 2      Arroyo Mocho
LOE ID:	274189
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Lead.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved lead criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 2.5 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141753, Lead Region 2      Arroyo Mocho
LOE ID:	274032
Pollutant:	Lead
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Lead .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for lead is the probable effect concentration (PEC) of 128 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141753, Lead Region 2      Arroyo Mocho
LOE ID:	274205
Pollutant:	Lead
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Lead .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for lead is the probable effect concentration (PEC) of 128 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141753, Lead Region 2      Arroyo Mocho
LOE ID:	274189
Pollutant:	Lead
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Lead .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for lead is the probable effect concentration (PEC) of 128 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141753, Lead Region 2      Arroyo Mocho
LOE ID:	284158
Pollutant:	Lead
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Lead.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved lead criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 2.5 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141753, Lead Region 2      Arroyo Mocho
LOE ID:	284262
Pollutant:	Lead
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Lead.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved lead criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 2.5 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141753, Lead Region 2      Arroyo Mocho
LOE ID:	95370
Pollutant:	Lead
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for arsenic, chromium VI, copper, lead, nickel, silver and zinc. Concentrations of total dissolved chromium were well below the objective for chromium VI.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Table 3-4 in the Basin Plan (2007) lists freshwater water quality objectives for toxic pollutants: arsenic- 150 ug/L, chromium VI- 11 ug/L, copper - 9.0 ug/L, lead - 2.5 ug/L; nickel - 52 ug/L, silver-3.4 ug/L and zinc - 120 ug/L.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed (above Vulcan Bridge Zone 7).
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:	There were no unusual environmental conditions associated with the sampling.
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141753, Lead Region 2      Arroyo Mocho
LOE ID:	95365
Pollutant:	Lead
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of arsenic, cadmium, chromium, copper, lead, mercury and zinc in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) arsenic - 33 mg/kg dw; cadmium - 4.98 mg/kg dw; chromium - 111 mg/kg dw; copper - 149 mg/kg dw; lead - 128 mg/kg dw; mercury - 1.06 mg/kg dw; nickel - 48.6 mg/kg dw; zinc - 459 mg/kg dw.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a "watershed integrator" site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:	There were no unusual environmental conditions associated with the sampling.
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

  Pollutant: Lead LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Lead . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for lead is the probable effect concentration (PEC) of 128 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141753, Lead	Region 2
Arroyo Mocho

  LOE ID: 284158   Pollutant: Lead LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Lead. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The dissolved lead criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 2.5 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2018-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 141753, Lead	Region 2
Arroyo Mocho

  LOE ID: 284262   Pollutant: Lead LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Lead. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The dissolved lead criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 2.5 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2018-05-16 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 141753, Lead	Region 2
Arroyo Mocho

  LOE ID: 95370   Pollutant: Lead LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for arsenic, chromium VI, copper, lead, nickel, silver and zinc. Concentrations of total dissolved chromium were well below the objective for chromium VI. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Table 3-4 in the Basin Plan (2007) lists freshwater water quality objectives for toxic pollutants: arsenic- 150 ug/L, chromium VI- 11 ug/L, copper - 9.0 ug/L, lead - 2.5 ug/L; nickel - 52 ug/L, silver-3.4 ug/L and zinc - 120 ug/L. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed (above Vulcan Bridge Zone 7). Temporal Representation: Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005. Environmental Conditions: There were no unusual environmental conditions associated with the sampling. QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)  

Line of Evidence (LOE) for Decision ID 141753, Lead	Region 2
Arroyo Mocho

  LOE ID: 95365   Pollutant: Lead LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of arsenic, cadmium, chromium, copper, lead, mercury and zinc in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) arsenic - 33 mg/kg dw; cadmium - 4.98 mg/kg dw; chromium - 111 mg/kg dw; copper - 149 mg/kg dw; lead - 128 mg/kg dw; mercury - 1.06 mg/kg dw; nickel - 48.6 mg/kg dw; zinc - 459 mg/kg dw. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a "watershed integrator" site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: There were no unusual environmental conditions associated with the sampling. QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)  

DECISION ID	141754	Region 2
Arroyo Mocho

Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141754, Lindane/gamma Hexachlorocyclohexane (gamma-HCH) Region 2      Arroyo Mocho
LOE ID:	273677
Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for HCH, gamma- .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for lindane is the probable effect concentration (PEC) for Lindane is 4.99 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:
DECISION ID	141754	Region 2
Arroyo Mocho

Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141754, Lindane/gamma Hexachlorocyclohexane (gamma-HCH) Region 2      Arroyo Mocho
LOE ID:	273677
Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for HCH, gamma- .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for lindane is the probable effect concentration (PEC) for Lindane is 4.99 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141754, Lindane/gamma Hexachlorocyclohexane (gamma-HCH) Region 2      Arroyo Mocho
LOE ID:	290083
Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for PCBs, Chlorpyrifos, Dacthal, diazinon, disulfoton, endosulfan, Lindane/gamma Hexachlorocyclohexane (gamma-HCH), methyl parathion, thiobencarb.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.Diazinon water quality objective, 0.1 ug/L (acute)
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	PCBs - 0.014 ug/L freshwater continuous Concentration; Chlorpyrifos - 0.015 ug/L (chronic); Dacthal (DCPA) - 14300 ug/L (acute); Disulfoton (Disyston) - 0.05 ug/L (acute); Endosulfan - 0.056 ug/L (chronic)/0.22 ug/L (acute); HCH, gamma-(gamma BHC, Lindane) - 0.95 ug/L (acute); methyl parathion - 0.08 ug/L (acute); Thiobencarb - 3.1 ug/L (acute).
Guideline Reference:	National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed.
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141754, Lindane/gamma Hexachlorocyclohexane (gamma-HCH) Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141754, Lindane/gamma Hexachlorocyclohexane (gamma-HCH) Region 2      Arroyo Mocho   LOE ID: 290083   Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for PCBs, Chlorpyrifos, Dacthal, diazinon, disulfoton, endosulfan, Lindane/gamma Hexachlorocyclohexane (gamma-HCH), methyl parathion, thiobencarb. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.Diazinon water quality objective, 0.1 ug/L (acute) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: PCBs - 0.014 ug/L freshwater continuous Concentration; Chlorpyrifos - 0.015 ug/L (chronic); Dacthal (DCPA) - 14300 ug/L (acute); Disulfoton (Disyston) - 0.05 ug/L (acute); Endosulfan - 0.056 ug/L (chronic)/0.22 ug/L (acute); HCH, gamma-(gamma BHC, Lindane) - 0.95 ug/L (acute); methyl parathion - 0.08 ug/L (acute); Thiobencarb - 3.1 ug/L (acute). Guideline Reference: National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA   Spatial Representation: Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed. Temporal Representation: Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 141754, Lindane/gamma Hexachlorocyclohexane (gamma-HCH) Region 2      Arroyo Mocho   LOE ID: 273845   Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for HCH, gamma- . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for lindane is the probable effect concentration (PEC) for Lindane is 4.99 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141754, Lindane/gamma Hexachlorocyclohexane (gamma-HCH) Region 2      Arroyo Mocho   LOE ID: 273716   Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 0 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for HCH, gamma-. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Se%; PADDING-LEFT: 0%; FONT-WEIGHT: bold; PADDING-BOTTOM: 3px; WIDTH: 100%; text-align: right; PADDING-TOP: 3px; font-smooth: always">Region 2      Arroyo Mocho
LOE ID:	273845
Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for HCH, gamma- .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for lindane is the probable effect concentration (PEC) for Lindane is 4.99 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141754, Lindane/gamma Hexachlorocyclohexane (gamma-HCH) Region 2      Arroyo Mocho
LOE ID:	273716
Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	0
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for HCH, gamma-. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for lindane is the probable effect concentration (PEC) for Lindane is 4.99 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Date for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141754, Lindane/gamma Hexachlorocyclohexane (gamma-HCH) Region 2      Arroyo Mocho
LOE ID:	290030
Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141754, Lindane/gamma Hexachlorocyclohexane (gamma-HCH) Region 2      Arroyo Mocho
LOE ID:	273676
Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	0
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for HCH, gamma-. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for lindane is the probable effect concentration (PEC) for Lindane is 4.99 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Date for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

ction 6.1.5.5. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for lindane is the probable effect concentration (PEC) for Lindane is 4.99 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Date for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141754, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 2
Arroyo Mocho

  LOE ID: 290030   Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)  

Line of Evidence (LOE) for Decision ID 141754, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 2
Arroyo Mocho

  LOE ID: 273676   Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 0 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for HCH, gamma-. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for lindane is the probable effect concentration (PEC) for Lindane is 4.99 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Date for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

DECISION ID	145414	Region 2
Arroyo Mocho

Pollutant:	Mercury
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 145414, Mercury Region 2      Arroyo Mocho
LOE ID:	274309
Pollutant:	Mercury
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Mercury .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for mercury is the probable effect concentration (PEC) of 1.06 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshw   DECISION ID 145414 Region 2      Arroyo Mocho   Pollutant: Mercury Final Listing Decision: Do Not List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: New Decision Revision Status Revised Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.   Listing Extent:     Line of Evidence (LOE) for Decision ID 145414, Mercury Region 2      Arroyo Mocho   LOE ID: 274309   Pollutant: Mercury LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Mercury . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for mercury is the probable effect concentration (PEC) of 1.06 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 145414, Mercury Region 2      Arroyo Mocho   LOE ID: 284718   Pollutant: Mercury LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Mercury. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: National Recommended Water Quality Criteria Continuous Concentration (4-day average concentrations) for freshwater aquatic organisms exposure to total mercury is 0.77 ug/L. Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2018-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 145414, Mercury Region 2      Arroyo Mocho   LOE ID: 284762   Pollutant:   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 145414, Mercury Region 2      Arroyo Mocho   LOE ID: 284718   Pollutant: Mercury LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Mercury. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: National Recommended Water Quality Criteria Continuous Concentration (4-day average concentrations) for freshwater aquatic organisms exposure to total mercury is 0.77 ug/L. Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2018-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 145414, Mercury Region 2      Arroyo Mocho   LOE ID: 284762   Pollutant: Mercury LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Mercury. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: National Recommended Water Quality Criteria Continuous Concentration (4-day average concentrations) for freshwater aquatic organisms exposure to total mercury is 0.77 ug/L. Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2018-05-16 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 145414, Mercury Region 2      Arroyo Mocho   LOE ID: 284528   Pollutant: Mercury LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Mercury. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Mercury LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Mercury. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: National Recommended Water Quality Criteria Continuous Concentration (4-day average concentrations) for freshwater aquatic organisms exposure to total mercury is 0.77 ug/L. Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2018-05-16 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 145414, Mercury Region 2      Arroyo Mocho   LOE ID: 284528   Pollutant: Mercury LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Mercury. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: National Recommended Water Quality Criteria Continuous Concentration (4-day average concentrations) for freshwater aquatic organisms exposure to total mercury is 0.77 ug/L. Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2018-05-16 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 145414, Mercury Region 2      Arroyo Mocho   LOE ID: 274244   Pollutant: Mercury LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Mercury . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for mercury is the probable effect concentration (PEC) of 1.06 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: National Recommended Water Quality Criteria Continuous Concentration (4-day average concentrations) for freshwater aquatic organisms exposure to total mercury is 0.77 ug/L. Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2018-05-16 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 145414, Mercury Region 2      Arroyo Mocho   LOE ID: 274244   Pollutant: Mercury LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Mercury . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for mercury is the probable effect concentration (PEC) of 1.06 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 145414, Mercury Region 2      Arroyo Mocho   LOE ID: 274439   Pollutant: Mercury LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Mercury . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for mercury is the probable effect concentration (PEC) of 1.06 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 145414, Mercury Region 2      Arroyo Mocho   LOE ID: 284125   Pollutant: Mercury LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Mercury. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: National Recommended Water Quality Criteria Continuous Concentration (4-day average concentrations) for freshwater aquatic organisms exposure to total mercury is 0.77 ug/L. Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2018-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 145414, Mercury Region 2      Arroyo Mocho   LOE ID: 274429   Pollutant: Mercury LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Mercury . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for mercury is the probable effect concentration (PEC) of 1.06 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   TH: 100%; text-align: left; PADDING-TOP: 3px; font-smooth: always">Line of Evidence (LOE) for Decision ID 145414, Mercury Region 2      Arroyo Mocho
LOE ID:	274439
Pollutant:	Mercury
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Mercury .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for mercury is the probable effect concentration (PEC) of 1.06 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 145414, Mercury Region 2      Arroyo Mocho
LOE ID:	284125
Pollutant:	Mercury
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Mercury.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	National Recommended Water Quality Criteria Continuous Concentration (4-day average concentrations) for freshwater aquatic organisms exposure to total mercury is 0.77 ug/L.
Guideline Reference:	National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 145414, Mercury Region 2      Arroyo Mocho
LOE ID:	274429
Pollutant:	Mercury
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Mercury .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for mercury is the probable effect concentration (PEC) of 1.06 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

DECISION ID	141755	Region 2
Arroyo Mocho

Pollutant:	Methyl Parathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141755, Methyl Parathion Region 2      Arroyo Mocho
LOE ID:	290084
Pollutant:	Methyl Parathion
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for PCBs, Chlorpyrifos, Dacthal, diazinon, disulfoton, endosulfan, Lindane/gamma Hexachlorocyclohexane (gamma-HCH), methyl parathion, thiobencarb.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.Diazinon water quality objective, 0.1 ug/L (acute)
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	PCBs - 0.014 ug/L freshwater continuous Concentration; Chlorpyrifos - 0.015 ug/L (chronic); Dacthal (DCPA) - 14300 ug/L (acute); Disulfoton (Disyston) - 0.05 ug/L (acute); Endosulfan - 0.056 ug/L (chronic)/0.22 ug/L (acute); HCH, gamma-(gamma BHC, Lindane) - 0.95 ug/L (acute); methyl parathion - 0.08 ug/L (acute); Thiobencarb - 3.1 ug/L (acute).
Guideline Reference:	National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed.
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	141755	Region 2
Arroyo Mocho

Pollutant:	Methyl Parathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141755, Methyl Parathion Region 2      Arroyo Mocho
LOE ID:	290084
Pollutant:	Methyl Parathion
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for PCBs, Chlorpyrifos, Dacthal, diazinon, disulfoton, endosulfan, Lindane/gamma Hexachlorocyclohexane (gamma-HCH), methyl parathion, thiobencarb.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.Diazinon water quality objective, 0.1 ug/L (acute)
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	PCBs - 0.014 ug/L freshwater continuous Concentration; Chlorpyrifos - 0.015 ug/L (chronic); Dacthal (DCPA) - 14300 ug/L (acute); Disulfoton (Disyston) - 0.05 ug/L (acute); Endosulfan - 0.056 ug/L (chronic)/0.22 ug/L (acute); HCH, gamma-(gamma BHC, Lindane) - 0.95 ug/L (acute); methyl parathion - 0.08 ug/L (acute); Thiobencarb - 3.1 ug/L (acute).
Guideline Reference:	National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed.
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	141756	Region 2
Arroyo Mocho

Pollutant:	Naphthalene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141756, Naphthalene Region 2      Arroyo Mocho
LOE ID:	290042
Pollutant:	Naphthalene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg;   DECISION ID 141756 Region 2      Arroyo Mocho   Pollutant: Naphthalene Final Listing Decision: Do Not List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: New Decision Revision Status Revised Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.   Listing Extent:     Line of Evidence (LOE) for Decision ID 141756, Naphthalene Region 2      Arroyo Mocho   LOE ID: 290042   Pollutant: Naphthalene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 141756, Naphthalene Region 2      Arroyo Mocho   LOE ID: 274857   Pollutant: Naphthalene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Naphthalene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for naphthalene is the probable effect concentration (PEC) of 561 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141756, Naphthalene Region 2      Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 141756, Naphthalene Region 2      Arroyo Mocho   LOE ID: 274857   Pollutant: Naphthalene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Naphthalene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for naphthalene is the probable effect concentration (PEC) of 561 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141756, Naphthalene Region 2      Arroyo Mocho   LOE ID: 274677   Pollutant: Naphthalene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Naphthalene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for naphthalene is the probable effect concentration (PEC) of 561 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141756, Naphthalene Region 2      Arroyo Mocho   LOE ID: 274902   Pollutant: Naphthalene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Naphthalene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for naphthalene is the probable effect concentration (PEC) of 561 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141756, Naphthalene Region 2      Arroyo Mocho   LOE ID: 274635   Pollutant: Naphthalene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Naphthalene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for naphthalene is the probable effect concentration (PEC) of 561 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   /div> Arroyo Mocho
LOE ID:	274677
Pollutant:	Naphthalene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Naphthalene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for naphthalene is the probable effect concentration (PEC) of 561 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141756, Naphthalene Region 2      Arroyo Mocho
LOE ID:	274902
Pollutant:	Naphthalene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Naphthalene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for naphthalene is the probable effect concentration (PEC) of 561 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141756, Naphthalene Region 2      Arroyo Mocho
LOE ID:	274635
Pollutant:	Naphthalene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Naphthalene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for naphthalene is the probable effect concentration (PEC) of 561 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

DECISION ID	141757	Region 2
Arroyo Mocho

Pollutant:	Nickel
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.6 of the Listing Policy. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 13 lines of evidence are available in the administrative record to assess this pollutant. 2 of the 2 sediment samples exceed the evaluation guideline. 0 of 2 samples exhibit sediment toxicity. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 2 of the 2 samples exceed the sediment evaluation guideline but 0 of 2 samples exceed the associated toxicity data and this sample size is SUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho
LOE ID:	274832
Pollutant:	Nickel
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Nickel .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for nickel is the probable effect concentration (PEC) of 48.6 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho
LOE ID:	268621
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	0 of the 1 samples collected by BASMAA RMC Monitoring in WY2014 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Growth (wt/surv indiv), Hyalella azteca for Survival.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:
DECISION ID	141757	Region 2
Arroyo Mocho

Pollutant:	Nickel
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.6 of the Listing Policy. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 13 lines of evidence are available in the administrative record to assess this pollutant. 2 of the 2 sediment samples exceed the evaluation guideline. 0 of 2 samples exhibit sediment toxicity. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 2 of the 2 samples exceed the sediment evaluation guideline but 0 of 2 samples exceed the associated toxicity data and this sample size is SUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

align="left" valign="top" width="67%">Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013Nickel

Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho
LOE ID:	274832
Pollutant:	Nickel
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Nickel .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for nickel is the probable effect concentration (PEC) of 48.6 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho
LOE ID:	268621
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	0 of the 1 samples collected by BASMAA RMC Monitoring in WY2014 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Growth (wt/surv indiv), Hyalella azteca for Survival.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00292 ( Arroyo Mocho just upstream of confluence with Arroyo de la Laguna ).
Temporal Representation:	The samples were collected between the dates of 2014-07-23 and 2014-07-23.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho
LOE ID:	268662
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	0 of the 1 samples collected by BASMAA RMC Monitoring in WY2014 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Growth (wt/surv indiv), Hyalella azteca for Survival.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00292 ( Arroyo Mocho just upstream of confluence with Arroyo de la Laguna ).
Temporal Representation:	The samples were collected between the dates of 2014-07-23 and 2014-07-23.
Spatial Representation:	The samples were collected at monitoring site: 204R00292 ( Arroyo Mocho just upstream of confluence with Arroyo de la Laguna ).
Temporal Representation:	The samples were collected between the dates of 2014-07-23 and 2014-07-23.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho
LOE ID:	268662
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	0 of the 1 samples collected by BASMAA RMC Monitoring in WY2014 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Growth (wt/surv indiv), Hyalella azteca for Survival.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00292 ( Arroyo Mocho just upstream of confluence with Arroyo de la Laguna ).
Temporal Representation:	The samples were collected between the dates of 2014-07-23 and 2014-07-23.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho
LOE ID:	268690
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	0 of the 1 samples collected by BASMAA RMC Monitoring in WY2012 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Survival, Hyalella azteca for Growth (wt/surv indiv).
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00100 ( Arroyo Mocho_BA_2012-204R00100 ).
Temporal Representation:	The samples were collected between the dates of 2012-07-25 and 2012-07-25.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho   LOE ID: 268690   Pollutant: Toxicity LOE Subgroup: Toxicity Matrix: Sediment Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: TOXICITY TESTING Data Used to Assess Water Quality: 0 of the 1 samples collected by BASMAA RMC Monitoring in WY2012 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Survival, Hyalella azteca for Growth (wt/surv indiv). Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated. Guideline Reference: Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013   Spatial Representation: The samples were collected at monitoring site: 204R00100 ( Arroyo Mocho_BA_2012-204R00100 ). Temporal Representation: The samples were collected between the dates of 2012-07-25 and 2012-07-25. Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho   LOE ID: 268682   Pollutant: Toxicity LOE Subgroup: Toxicity Matrix: Sediment Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: TOXICITY TESTING Data Used to Assess Water Quality: 0 of the 1 samples collected by BASMAA RMC Monitoring in WY2012 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Survival, Hyalella azteca for Growth (wt/surv indiv). Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated. Guideline Reference: Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013   Spatial Representation: The samples were collected at monitoring site: 204R00100 ( Arroyo Mocho_BA_2012-204R00100 ). Temporal Representation: The samples were collected between the dates of 2012-07-25 and 2012-07-25. Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho   LOE ID: 284716   Pollutant: Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho
LOE ID:	268682
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	0 of the 1 samples collected by BASMAA RMC Monitoring in WY2012 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Survival, Hyalella azteca for Growth (wt/surv indiv).
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00100 ( Arroyo Mocho_BA_2012-204R00100 ).
Temporal Representation:	The samples were collected between the dates of 2012-07-25 and 2012-07-25.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho
LOE ID:	284716
Pollutant:	Nickel
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Nickel.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved nickel criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 52 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho
LOE ID:	274722
Pollutant:	Nickel
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Nickel .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Nickel.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved nickel criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 52 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho
LOE ID:	274722
Pollutant:	Nickel
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Nickel .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for nickel is the probable effect concentration (PEC) of 48.6 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho
LOE ID:	284674
Pollutant:	Nickel
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Nickel.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved nickel criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 52 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho
Evaluation Guideline:	The evaluation guideline for nickel is the probable effect concentration (PEC) of 48.6 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho
LOE ID:	284674
Pollutant:	Nickel
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Nickel.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved nickel criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 52 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho
LOE ID:	284438
Pollutant:	Nickel
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Nickel.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved nickel criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 52 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho
LOE ID:	275102
Pollutant:	Nickel
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Nickel .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	LOE ID:	284438
Pollutant:	Nickel
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Nickel.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved nickel criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 52 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho
LOE ID:	275102
Pollutant:	Nickel
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Nickel .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for nickel is the probable effect concentration (PEC) of 48.6 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho
LOE ID:	274960
Pollutant:	Nickel
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Nickel .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for nickel is the probable effect concentration (PEC) of 48.6 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141757, Nickel Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for nickel is the probable effect concentration (PEC) of 48.6 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho   LOE ID: 274960   Pollutant: Nickel LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Nickel . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for nickel is the probable effect concentration (PEC) of 48.6 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho   LOE ID: 28754   Pollutant: Nickel LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentration of nickel in one sediment sample collected in spring 2005 exceeded the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (threshold effect concentration) nickel - 48.6 mg/kg dw. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a "watershed integrator" site located close to the mouth of Arroyo Mocho watershed. The PEC was exceeded for Nickel, with a sample concentration of 116 mg/kg dw. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s):   Line of Evidence (LOE) for Decision ID 141757, Nickel Region 2      Arroyo Mocho   LOE ID: 284670   Pollutant: Nickel LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Nickel. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The dissolved nickel criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 52 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2018-05-16 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   bold; PADDING-BOTTOM: 3px; WIDTH: 100%; text-align: right; PADDING-TOP: 3px; font-smooth: always">Region 2
Arroyo Mocho

  LOE ID: 28754   Pollutant: Nickel LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentration of nickel in one sediment sample collected in spring 2005 exceeded the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (threshold effect concentration) nickel - 48.6 mg/kg dw. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a "watershed integrator" site located close to the mouth of Arroyo Mocho watershed. The PEC was exceeded for Nickel, with a sample concentration of 116 mg/kg dw. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s):  

Line of Evidence (LOE) for Decision ID 141757, Nickel	Region 2
Arroyo Mocho

  LOE ID: 284670   Pollutant: Nickel LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Nickel. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The dissolved nickel criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 52 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2018-05-16 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

DECISION ID	141758	Region 2
Arroyo Mocho

Pollutant:	Oxygen, Dissolved
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. One of fifty-one samples exceed the Basin Plan objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. One of fifty-one samples exceed the Basin Plan objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho
LOE ID:	28625
Pollutant:	Oxygen, Dissolved
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	12
Number of Exceedances:	3
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Comprehensive water quality assessment was conducted at Arroyo Mocho watershed as part of SWAMP assessment in 2004 and 2005. Continuous field monitoring of temperature, dissolved oxygen, pH, and specific conductance to determine temporal variability in basic water quality at one or two locations. The 7 day average minimum concentration of dissolved oxygen ranged from 0.2 to 10.5 mg/L and varied with season. Minimum dissolved oxygen levels fell below the objective of 5 mg/L at two locations in spring (April 2004) and one in the summer (August 2004) sampling events. The 7 day average concentration levels were 3.7, 0.7 (all spring) and 0.2 (summer) mg/L DO.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Obje   DECISION ID 141758 Region 2      Arroyo Mocho   Pollutant: Oxygen, Dissolved Final Listing Decision: Do Not List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2018) Revision Status Revised Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. One of fifty-one samples exceed the Basin Plan objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. One of fifty-one samples exceed the Basin Plan objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.   Listing Extent:     "top" width="67%">Beneficial Use: < colspan="2">Guideline Reference: Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 28625   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 12 Number of Exceedances: 3   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Comprehensive water quality assessment was conducted at Arroyo Mocho watershed as part of SWAMP assessment in 2004 and 2005. Continuous field monitoring of temperature, dissolved oxygen, pH, and specific conductance to determine temporal variability in basic water quality at one or two locations. The 7 day average minimum concentration of dissolved oxygen ranged from 0.2 to 10.5 mg/L and varied with season. Minimum dissolved oxygen levels fell below the objective of 5 mg/L at two locations in spring (April 2004) and one in the summer (August 2004) sampling events. The 7 day average concentration levels were 3.7, 0.7 (all spring) and 0.2 (summer) mg/L DO. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The numeric water quality objective for dissolved oxygen is 5.0 mg/L minimum for waters designated as warm water habitat. The median dissolved oxygen concentration for any three consecutive months shall not be less than 80 percent of the dissolved oxygen content at saturation. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: Dissolved oxygen was measured at two sites in summer 2004 and five sites in spring 2004 and winter 2005. Temporal Representation: At all locations the SWAMP performed continuous monitoring of dissolved oxygen at 15 minute intervals lasting 7-13 days during spring (April 2004), summer dry season (August 2004), and winter wet season (February 2005). Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002). QAPP Information Reference(s):   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285459   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: The numeric water quality objective for dissolved oxygen is 5.0 mg/L minimum for waters designated as warm water habitat. The median dissolved oxygen concentration for any three consecutive months shall not be less than 80 percent of the dissolved oxygen content at saturation. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: Dissolved oxygen was measured at two sites in summer 2004 and five sites in spring 2004 and winter 2005. Temporal Representation: At all locations the SWAMP performed continuous monitoring of dissolved oxygen at 15 minute intervals lasting 7-13 days during spring (April 2004), summer dry season (August 2004), and winter wet season (February 2005). Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002). QAPP Information Reference(s):   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285459   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285793   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285794   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: 285793   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285794   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286535   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd). Temporal Representation: The samples were collected between the dates of 2019-04-30 and 2019-04-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286169   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286535   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd). Temporal Representation: The samples were collected between the dates of 2019-04-30 and 2019-04-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286169   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285943   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-02 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. T Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285943   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-02 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286474   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285773   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 6 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as followshis is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286474   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285773   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 6 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285918   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 4 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-05-30 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285918   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 4 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-05-30 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286148   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285962   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286148   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285962   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286217   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID:tr>   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286217   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286093   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 12 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 12 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-08-26 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286135   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: 286093   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 12 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 12 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-08-26 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286135   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd). Temporal Representation: The samples were collected between the dates of 2019-04-30 and 2019-04-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285919   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 12 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 12 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-08-26 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286053   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd). Temporal Representation: The samples were collected between the dates of 2019-04-30 and 2019-04-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285919   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 12 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 12 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-08-26 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286053   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-03 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285432   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 6 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-03 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285432   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 6 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285744   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285961   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Qualityd align="left" valign="top" width="67%"> QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285744   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285961   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286131   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Statu: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286131   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286554   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 7 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286075   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference:   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286554   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 7 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286075   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285460   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285460   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285691   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 6 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-07-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285772   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objec-align: right; PADDING-TOP: 3px; font-smooth: always">Region 2      Arroyo Mocho   LOE ID: 285691   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 6 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-07-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285772   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286072   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286072   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286434   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285685   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 6 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: 286434   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285685   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 6 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-07-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286602   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-02 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286214   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total     Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-07-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286602   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-02 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286214   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286168   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286168   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286046   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286506   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 4 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality thresht" valign="top" width="33%">QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286046   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286506   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 4 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-05-30 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285030   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 7 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-05-30 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285030   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 7 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as cold water habitat shall be of a 7.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 285771   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-03 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 286338   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho   LOE ID: 28624   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 12 Number of Exceedances: 4   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Comprehensive water quality assessment was conducted at Arroyo Mocho watershed as part of SWAMP assessment in 2004 and 2005. Continuous field monitoring of temperature, dissolved oxygen, pH, and specific conductance to determine temporal variability in basic water quality at one or two locations. The 7 day average minimum concentration of dissolved oxygen ranged from 0.2 to 10.5 mg/L and varied with season. Minimum dissolved oxygen levels fell below the objective of 7 mg/L at three locations in spring (April 2004) and one in the summer (August 2003) sampling events. The 7 day average concentration levels were 6.5, 3.7, 0.7 (all spring) and 0.2 (summer) mg/L DO. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The numeric water quality objective for dissolved oxygen is 7.0 mg/L minimum for waters designated as cold water habitat. The median dissolved oxygen concentration for any three consecutive months shall not be less than 80 percent of the dissolved oxygen content at saturation. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: Dissolved oxygen was measured at two or five sites located on the mainstem of San Mateo Creek that are representative of the entire creek length. Temporal Representation: At all locations the SWAMP performed continuous monitoring of dissolved oxygen at 15 minute intervals lasting 7-13 days during spring (April 2004), summer dry season (August 2004), and winter wet season (February 2004). Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002). QAPP Information Reference(s):   idth="75%"> Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho
LOE ID:	285771
Pollutant:	Oxygen, Dissolved
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.)
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-04-03
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho
LOE ID:	286338
Pollutant:	Oxygen, Dissolved
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.)
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473).
Temporal Representation:	The samples were collected between the dates of 2013-05-09 and 2013-05-09
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141758, Oxygen, Dissolved Region 2      Arroyo Mocho
LOE ID:	28624
Pollutant:	Oxygen, Dissolved
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	12
Number of Exceedances:	4
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Comprehensive water quality assessment was conducted at Arroyo Mocho watershed as part of SWAMP assessment in 2004 and 2005. Continuous field monitoring of temperature, dissolved oxygen, pH, and specific conductance to determine temporal variability in basic water quality at one or two locations. The 7 day average minimum concentration of dissolved oxygen ranged from 0.2 to 10.5 mg/L and varied with season. Minimum dissolved oxygen levels fell below the objective of 7 mg/L at three locations in spring (April 2004) and one in the summer (August 2003) sampling events. The 7 day average concentration levels were 6.5, 3.7, 0.7 (all spring) and 0.2 (summer) mg/L DO.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The numeric water quality objective for dissolved oxygen is 7.0 mg/L minimum for waters designated as cold water habitat. The median dissolved oxygen concentration for any three consecutive months shall not be less than 80 percent of the dissolved oxygen content at saturation.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Dissolved oxygen was measured at two or five sites located on the mainstem of San Mateo Creek that are representative of the entire creek length.
Temporal Representation:	At all locations the SWAMP performed continuous monitoring of dissolved oxygen at 15 minute intervals lasting 7-13 days during spring (April 2004), summer dry season (August 2004), and winter wet season (February 2004).
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002).
QAPP Information Reference(s):

DECISION ID	148799	Region 2
Arroyo Mocho

Pollutant:	PAHs (Polycyclic Aromatic Hydrocarbons)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
Listing Extent:

Line of Evidence (LOE) for Decision ID 148799, PAHs (Polycyclic Aromatic Hydrocarbons) Region 2      Arroyo Mocho
LOE ID:	275190
Pollutant:	PAHs (Polycyclic Aromatic Hydrocarbons)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for PAHs (Polycyclic Aromatic Hydrocarbons) .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for total PAHs is the probable effect concentration (PEC) of 22800 ug/kg dry weight (MacDonald et al., 2000a).
DECISION ID	148799	Region 2
Arroyo Mocho

Pollutant:	PAHs (Polycyclic Aromatic Hydrocarbons)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
Listing Extent:

Line of Evidence (LOE) for Decision ID 148799, PAHs (Polycyclic Aromatic Hydrocarbons) Region 2      Arroyo Mocho
LOE ID:	275190
Pollutant:	PAHs (Polycyclic Aromatic Hydrocarbons)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for PAHs (Polycyclic Aromatic Hydrocarbons) .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for total PAHs is the probable effect concentration (PEC) of 22800 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 148799, PAHs (Polycyclic Aromatic Hydrocarbons) Region 2      Arroyo Mocho
LOE ID:	275150
Pollutant:	PAHs (Polycyclic Aromatic Hydrocarbons)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for PAHs (Polycyclic Aromatic Hydrocarbons) .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for total PAHs is the probable effect concentration (PEC) of 22800 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 148799, PAHs (Polycyclic Aromatic Hydrocarbons) Region 2      Arrn="top" width="33%">Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 148799, PAHs (Polycyclic Aromatic Hydrocarbons) Region 2      Arroyo Mocho   LOE ID: 275150   Pollutant: PAHs (Polycyclic Aromatic Hydrocarbons) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for PAHs (Polycyclic Aromatic Hydrocarbons) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for total PAHs is the probable effect concentration (PEC) of 22800 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 148799, PAHs (Polycyclic Aromatic Hydrocarbons) Region 2      Arroyo Mocho   LOE ID: 275207   Pollutant: PAHs (Polycyclic Aromatic Hydrocarbons) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for PAHs (Polycyclic Aromatic Hydrocarbons) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for total PAHs is the probable effect concentration (PEC) of 22800 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 148799, PAHs (Polycyclic Aromatic Hydrocarbons) Region 2      Arroyo Mocho   LOE ID: 290043   Pollutant: PAHs (Polycyclic Aromatic Hydrocarbons) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 148799, PAHs (Polycyclic Aromatic Hydrocarbons) Region 2      Arroyo Mocho   LOE ID: 275211   Pollutant: PAHs (Polycyclic Aromatic Hydrocarbons) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for PAHs (Polycyclic Aromatic Hydrocarbons) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for total PAHs is the probable effect concentration (PEC) of 22800 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   oyo Mocho

  LOE ID: 275207   Pollutant: PAHs (Polycyclic Aromatic Hydrocarbons) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for PAHs (Polycyclic Aromatic Hydrocarbons) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for total PAHs is the probable effect concentration (PEC) of 22800 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 148799, PAHs (Polycyclic Aromatic Hydrocarbons)	Region 2
Arroyo Mocho

  LOE ID: 290043   Pollutant: PAHs (Polycyclic Aromatic Hydrocarbons) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)  

Line of Evidence (LOE) for Decision ID 148799, PAHs (Polycyclic Aromatic Hydrocarbons)	Region 2
Arroyo Mocho

  LOE ID: 275211   Pollutant: PAHs (Polycyclic Aromatic Hydrocarbons) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for PAHs (Polycyclic Aromatic Hydrocarbons) . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for total PAHs is the probable effect concentration (PEC) of 22800 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

DECISION ID	141761	Region 2
Arroyo Mocho

Pollutant:	PCBs (Polychlorinated biphenyls)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141761, PCBs (Polychlorinated biphenyls) Region 2      Arroyo Mocho
LOE ID:	290099
Pollutant:	PCBs (Polychlorinated biphenyls)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for PCBs, Chlorpyrifos, Dacthal, diazinon, disulfoton, endosulfan, Lindane/gamma Hexachlorocyclohexane (gamma-HCH), methyl parathion, thiobencarb.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.Diazinon water quality objective, 0.1 ug/L (acute)
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	PCBs - 0.014 ug/L freshwater continuous Concentration; Chlorpyrifos - 0.015 ug/L (chronic); Dacthal (DCPA) - 14300 ug/L (acute); Disulfoton (Disyston) - 0.05 ug/L (acute); Endosulfan - 0.056 ug/L (chronic)/0.22 ug/L (acute); HCH, gamma-(gamma BHC, Lindane) - 0.95 ug/L (acute); methyl parathion - 0.08 ug/L (acute); Thiobencarb - 3.1 ug/L (acute).
Guideline Reference:	National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed.
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141761, PCBs (Polychlorinated biphenyls) Region 2      Arroyo Mocho
LOE ID:	290044
Pollutant:	PCBs (Polychlorinated biphenyls)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	141761	Region 2
Arroyo Mocho

Pollutant:	PCBs (Polychlorinated biphenyls)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141761, PCBs (Polychlorinated biphenyls) Region 2      Arroyo Mocho
LOE ID:	290099
Pollutant:	PCBs (Polychlorinated biphenyls)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for PCBs, Chlorpyrifos, Dacthal, diazinon, disulfoton, endosulfan, Lindane/gamma Hexachlorocyclohexane (gamma-HCH), methyl parathion, thiobencarb.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.Diazinon water quality objective, 0.1 ug/L (acute)
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	PCBs - 0.014 ug/L freshwater continuous Concentration; Chlorpyrifos - 0.015 ug/L (chronic); Dacthal (DCPA) - 14300 ug/L (acute); Disulfoton (Disyston) - 0.05 ug/L (acute); Endosulfan - 0.056 ug/L (chronic)/0.22 ug/L (acute); HCH, gamma-(gamma BHC, Lindane) - 0.95 ug/L (acute); methyl parathion - 0.08 ug/L (acute); Thiobencarb - 3.1 ug/L (acute).
Guideline Reference:	National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed.
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141761, PCBs (Polychlorinated biphenyls) Region 2      Arroyo Mocho
LOE ID:	290044
Pollutant:	PCBs (Polychlorinated biphenyls)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	141779	Region 2
Arroyo Mocho

Pollutant:	Permethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141779, Permethrin Region 2      Arroyo Mocho
LOE ID:	275236
Pollutant:	Permethrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Permethrin, Total .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for permethrin is the median lethal concentration (LC50) of 8.9 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 8.9 ug/g is the geometric mean of LC50 values for permethrin (Amweg et al., 2005).
Guideline Reference:
DECISION ID	141779	Region 2
Arroyo Mocho

Pollutant:	Permethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141779, Permethrin Region 2      Arroyo Mocho
LOE ID:	275236
Pollutant:	Permethrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Permethrin, Total .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for permethrin is the median lethal concentration (LC50) of 8.9 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 8.9 ug/g is the geometric mean of LC50 values for permethrin (Amweg et al., 2005).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141779, Permethrin Region 2      Arroyo Mocho
LOE ID:	275336
Pollutant:	Permethrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Permethrin, Total .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for permethrin is the median lethal concentration (LC50) of 8.9 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 8.9 ug/g is the geometric mean of LC50 values for permethrin (Amweg et al., 2005).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141779, Permethrin Region 2      Arroyo Mocho
LOE ID:	275259
Pollutant:	Permethrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Permethrin, Total .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for permethrin is the median lethal concentration (LC50) of 8.9 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 8.9 ug/g is the geometric mean of LC50 values for permethrin (Amweg et al., 2005).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141779, Permethrin Region 2      Arroyo Mocho
LOE ID:	275457
Pollutant:	Permethrin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Permethrin, Total .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for permethrin is the median lethal concentration (LC50) of 8.9 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 8.9 ug/g is the geometric mean of LC50 values for permethrin (Amweg et al., 2005).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

gov/water_issues/programs/tmdl/records/state_board/2008/ref3311.pdf" >Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141779, Permethrin	Region 2
Arroyo Mocho

  LOE ID: 275336   Pollutant: Permethrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Permethrin, Total . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for permethrin is the median lethal concentration (LC50) of 8.9 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 8.9 ug/g is the geometric mean of LC50 values for permethrin (Amweg et al., 2005). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141779, Permethrin	Region 2
Arroyo Mocho

  LOE ID: 275259   Pollutant: Permethrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Permethrin, Total . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for permethrin is the median lethal concentration (LC50) of 8.9 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 8.9 ug/g is the geometric mean of LC50 values for permethrin (Amweg et al., 2005). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141779, Permethrin	Region 2
Arroyo Mocho

  LOE ID: 275457   Pollutant: Permethrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Permethrin, Total . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for permethrin is the median lethal concentration (LC50) of 8.9 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 8.9 ug/g is the geometric mean of LC50 values for permethrin (Amweg et al., 2005). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

DECISION ID	141760	Region 2
Arroyo Mocho

Pollutant:	Phenanthrene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141760, Phenanthrene Region 2      Arroyo Mocho
LOE ID:	290055
Pollutant:	Phenanthrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/k   DECISION ID 141760 Region 2      Arroyo Mocho   Pollutant: Phenanthrene Final Listing Decision: Do Not List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: New Decision Revision Status Revised Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.   Listing Extent:     Line of Evidence (LOE) for Decision ID 141760, Phenanthrene Region 2      Arroyo Mocho   LOE ID: 290055   Pollutant: Phenanthrene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 141760, Phenanthrene Region 2      Arroyo Mocho   LOE ID: 275479   Pollutant: Phenanthrene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Phenanthrene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for phenanthrene is the probable effect concentration (PEC) of 1170 ug/kg dry weight (MacDonald et al.). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141760, Phenanthrene Region 2     g; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 141760, Phenanthrene Region 2      Arroyo Mocho   LOE ID: 275479   Pollutant: Phenanthrene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Phenanthrene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for phenanthrene is the probable effect concentration (PEC) of 1170 ug/kg dry weight (MacDonald et al.). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141760, Phenanthrene Region 2      Arroyo Mocho   LOE ID: 275790   Pollutant: Phenanthrene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Phenanthrene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for phenanthrene is the probable effect concentration (PEC) of 1170 ug/kg dry weight (MacDonald et al.). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141760, Phenanthrene Region 2      Arroyo Mocho   LOE ID: 275507   Pollutant: Phenanthrene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Phenanthrene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for phenanthrene is the probable effect concentration (PEC) of 1170 ug/kg dry weight (MacDonald et al.). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141760, Phenanthrene Region 2      Arroyo Mocho   LOE ID: 275768   Pollutant: Phenanthrene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Phenanthrene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for phenanthrene is the probable effect concentration (PEC) of 1170 ug/kg dry weight (MacDonald et al.). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   ; Arroyo Mocho
LOE ID:	275790
Pollutant:	Phenanthrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Phenanthrene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for phenanthrene is the probable effect concentration (PEC) of 1170 ug/kg dry weight (MacDonald et al.).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141760, Phenanthrene Region 2      Arroyo Mocho
LOE ID:	275507
Pollutant:	Phenanthrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Phenanthrene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for phenanthrene is the probable effect concentration (PEC) of 1170 ug/kg dry weight (MacDonald et al.).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141760, Phenanthrene Region 2      Arroyo Mocho
LOE ID:	275768
Pollutant:	Phenanthrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Phenanthrene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for phenanthrene is the probable effect concentration (PEC) of 1170 ug/kg dry weight (MacDonald et al.).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

DECISION ID	141762	Region 2
Arroyo Mocho

Pollutant:	Pyrene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141762, Pyrene Region 2      Arroyo Mocho
LOE ID:	275659
Pollutant:	Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Pyrene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for pyrene is the probable effect concentration (PEC) of 1520 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater   DECISION ID 141762 Region 2      Arroyo Mocho   Pollutant: Pyrene Final Listing Decision: Do Not List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: New Decision Revision Status Revised Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.   Listing Extent:     Line of Evidence (LOE) for Decision ID 141762, Pyrene Region 2      Arroyo Mocho   LOE ID: 275659   Pollutant: Pyrene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Pyrene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for pyrene is the probable effect concentration (PEC) of 1520 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141762, Pyrene Region 2      Arroyo Mocho   LOE ID: 275817   Pollutant: Pyrene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Pyrene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for pyrene is the probable effect concentration (PEC) of 1520 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141762, Pyrene Region 2      Arroyo Mocho   LOE ID: 290056   Pollutant: Pyrene LOE Subgroup:   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141762, Pyrene Region 2      Arroyo Mocho   LOE ID: 275817   Pollutant: Pyrene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Pyrene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for pyrene is the probable effect concentration (PEC) of 1520 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141762, Pyrene Region 2      Arroyo Mocho   LOE ID: 290056   Pollutant: Pyrene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg. Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed. Temporal Representation: Sediment sample was collected in April of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 141762, Pyrene Region 2      Arroyo Mocho   LOE ID: 275661   Pollutant: Pyrene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Pyrene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for pyrene is the probable effect concentration (PEC) of 1520 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141762, Pyrene Region 2      Arroyo Mocho   LOE ID: 275577   Pollutant: Pyrene LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Pyrene . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for pyrene is the probable effect concentration (PEC) of 1520 ug/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   th="67%">Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of Anthracene, fluorene, napthalene, phenanthrene, benz(a)anthracene, benzo(a)pyrene, chrysene, fluoranthrene, pyrene, PAH (total), PCB (total), chlordane, dieldrin, DDD/DDE/DDT, endrin, heptachlor epoxide, and HCH, gamma in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) Anthracene - 845 ug/kg; Fluorene - 536 ug/kg; Naphthalene - 561 ug/kg; Phenanthrene -1170 ug/kg; Benz(a)anthracene - 1050 ug/kg; Benzo(a)pyrene - 1450 ug/kg; Chrysene - 1290 ug/kg; Fluoranthene - 2230 ug/kg; Pyrene - 1520 ug/kg; PAH (total) - 22800 ug/kg; PCB (total) - 676 ug/kg; Chlordane - 17.6 ug/kg; Dieldrin - 61.8 ug/kg; DDD (sum op + pp) - 28 ug/kg; DDE (sum op + pp) - 31.3 ug/kg; DDT (sum op + pp) - 62.9 ug/kg; DDT (total) - 572 ug/kg; Endrin - 207 ug/kg; Heptachlor epoxide - 16 ug/kg; HCH, gamma - 4.99 ug/kg.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a watershed integrator site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141762, Pyrene Region 2      Arroyo Mocho
LOE ID:	275661
Pollutant:	Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Pyrene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for pyrene is the probable effect concentration (PEC) of 1520 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141762, Pyrene Region 2      Arroyo Mocho
LOE ID:	275577
Pollutant:	Pyrene
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Pyrene .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for pyrene is the probable effect concentration (PEC) of 1520 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

DECISION ID	141770	Region 2
Arroyo Mocho

Pollutant:	Pyrethroids
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141770, Pyrethroids Region 2      Arroyo Mocho
LOE ID:	275863
Pollutant:	Pyrethroids
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Pyrethroids .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the protection of aquatic life from pyrethroids is one toxic unit. Individual pyrethroid concentrations in sediment were normalized to organic carbon content, divided by the respective LC50 and then summed. A sum over over one toxic unit is an exceedance of the evaluation guideline (Amweg et al. 2006).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Guideline Reference:	Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15
Guideline Reference:	Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.
Guideline Reference:	Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.
Guideline Reference:	Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids
Guideline Reference:	Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141770, Pyrethroids Region 2      Arroyo Mocho
LOE ID:	275726
Pollutant:	Pyrethroids
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Pyrethroids .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the protection of aquatic life from pyrethroids is one toxic unit. Individual pyrethroid concentrations in sediment were normalized to organic carbon content, divided by the respective LC50 and then summed. A sum over over one toxic unit is an exceedance of the evaluation guideline (Amweg et al. 2006).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Guideline Reference:
DECISION ID	141770	Region 2
Arroyo Mocho

Pollutant:	Pyrethroids
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141770, Pyrethroids Region 2      Arroyo Mocho
LOE ID:	275863
Pollutant:	Pyrethroids
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Pyrethroids .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the protection of aquatic life from pyrethroids is one toxic unit. Individual pyrethroid concentrations in sediment were normalized to organic carbon content, divided by the respective LC50 and then summed. A sum over over one toxic unit is an exceedance of the evaluation guideline (Amweg et al. 2006).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Guideline Reference:	Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15
Guideline Reference:	Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.
Guideline Reference:	Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.
Guideline Reference:	Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids
Guideline Reference:	Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141770, Pyrethroids Region 2      Arroyo Mocho
LOE ID:	275726
Pollutant:	Pyrethroids
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Pyrethroids .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the protection of aquatic life from pyrethroids is one toxic unit. Individual pyrethroid concentrations in sediment were normalized to organic carbon content, divided by the respective LC50 and then summed. A sum over over one toxic unit is an exceedance of the evaluation guideline (Amweg et al. 2006).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Guideline Reference:	Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15
Guideline Reference:	Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.
Guideline Reference:	Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.
Guideline Reference:	Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids
Guideline Reference:	Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141770, Pyrethroids Region 2      Arroyo Mocho
LOE ID:	276061
Pollutant:	Pyrethroids
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Pyrethroids .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the protection of aquatic life from pyrethroids is one toxic unit. Individual pyrethroid concentrations in sediment were normalized to organic carbon content, divided by the respective LC50 and then summed. A sum over over one toxic unit is an exceedance of the evaluation guideline (Amweg et al. 2006).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Guideline Reference:	Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15
Guideline Reference:	Toxiww.waterboards.ca.gov/water_issues/programs/tmdl/records/state_board/2010/ref3820.pdf" >Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15
Guideline Reference:	Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.
Guideline Reference:	Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.
Guideline Reference:	Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids
Guideline Reference:	Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141770, Pyrethroids Region 2      Arroyo Mocho
LOE ID:	276061
Pollutant:	Pyrethroids
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Pyrethroids .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the protection of aquatic life from pyrethroids is one toxic unit. Individual pyrethroid concentrations in sediment were normalized to organic carbon content, divided by the respective LC50 and then summed. A sum over over one toxic unit is an exceedance of the evaluation guideline (Amweg et al. 2006).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Guideline Reference:	Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15
Guideline Reference:	Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.
Guideline Reference:	Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.
Guideline Reference:	Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids
Guideline Reference:	Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141770, Pyrethroids Region 2      Arroyo Mocho
LOE ID:	275916
Pollutant:	Pyrethroids
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Pyrethroids .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for the protection of aquatic life from pyrethroids is one toxic unit. Individual pyrethroid concentrations in sediment were normalized to organic carbon content, divided by the respective LC50 and then summed. A sum over over one toxic unit is an exceedance of the evaluation guideline (Amweg et al. 2006).
Guideline Reference:	Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Guideline Reference:	Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15
Guideline Reference:	Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.
Guideline Reference:	Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.
Guideline Reference:	Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids
Guideline Reference:	Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

city of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92. Guideline Reference: Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396. Guideline Reference: Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids Guideline Reference: Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141770, Pyrethroids	Region 2
Arroyo Mocho

  LOE ID: 275916   Pollutant: Pyrethroids LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Pyrethroids . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for the protection of aquatic life from pyrethroids is one toxic unit. Individual pyrethroid concentrations in sediment were normalized to organic carbon content, divided by the respective LC50 and then summed. A sum over over one toxic unit is an exceedance of the evaluation guideline (Amweg et al. 2006). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5 Guideline Reference: Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15 Guideline Reference: Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92. Guideline Reference: Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396. Guideline Reference: Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids Guideline Reference: Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

DECISION ID	141763	Region 2
Arroyo Mocho

Pollutant:	Selenium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141763, Selenium Region 2      Arroyo Mocho
LOE ID:	287791
Pollutant:	Selenium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Selenium.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:
DECISION ID	141763	Region 2
Arroyo Mocho

Pollutant:	Selenium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141763, Selenium Region 2      Arroyo Mocho
LOE ID:	287791
Pollutant:	Selenium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Selenium.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141763, Selenium Region 2      Arroyo Mocho
LOE ID:	287518
Pollutant:	Selenium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Selenium.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141763, Selenium Region 2      Arroyo Mocho
LOE ID:	288097
Pollutant:	Selenium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Selenium.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141763, Selenium Region 2      Arroyo Mocho
LOE ID:	287770
Pollutant:	Selenium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Selenium.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

d> The samples were collected between the dates of 2018-05-16 and 2018-05-16 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 141763, Selenium	Region 2
Arroyo Mocho

  LOE ID: 287518   Pollutant: Selenium LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Selenium. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2018-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 141763, Selenium	Region 2
Arroyo Mocho

  LOE ID: 288097   Pollutant: Selenium LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Selenium. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2018-05-16 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 141763, Selenium	Region 2
Arroyo Mocho

  LOE ID: 287770   Pollutant: Selenium LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Selenium. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2018-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

DECISION ID	141764	Region 2
Arroyo Mocho

Pollutant:	Silver
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141764, Silver Region 2      Arroyo Mocho
LOE ID:	287979
Pollutant:	Silver
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Silver.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved silver criterion maximum concentration (CMC) to protect aquatic life in freshwater is hardnesss dependent. The criterion when calculated using a default hardness of 100 mg/L is 3.4 ug/L. This criterion was divided by 2 in order to better represent a CMC value as specified in footnote (g) of Table (b)(1) of the California Toxics Rule, 2000.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141764, Silver Region 2      Arroyo Mocho
LOE ID:	288106
Pollutant:	Silver
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Silver.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved silver criterion maximum concentration (CMC) to protect aquatic life in freshwater is hardnesss dependent. The criterion when calculated using a default hardness of 100 mg/L is 3.4 ug/L. This criterion was divided by 2 in order to better represent a CMC value as specified in footnote (g) of Table (b)(1) of the California Toxics Rule, 2000.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141764, Silver Region 2      Arroyo Mocho
LOE ID:	288043
Pollutant:	Silver
LOE Subgroup:	Pol   DECISION ID 141764 Region 2      Arroyo Mocho   Pollutant: Silver Final Listing Decision: Do Not List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2018) Revision Status Revised Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.   Listing Extent:     Line of Evidence (LOE) for Decision ID 141764, Silver Region 2      Arroyo Mocho   LOE ID: 287979   Pollutant: Silver LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Silver. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The dissolved silver criterion maximum concentration (CMC) to protect aquatic life in freshwater is hardnesss dependent. The criterion when calculated using a default hardness of 100 mg/L is 3.4 ug/L. This criterion was divided by 2 in order to better represent a CMC value as specified in footnote (g) of Table (b)(1) of the California Toxics Rule, 2000. Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Silver. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The dissolved silver criterion maximum concentration (CMC) to protect aquatic life in freshwater is hardnesss dependent. The criterion when calculated using a default hardness of 100 mg/L is 3.4 ug/L. This criterion was divided by 2 in order to better represent a CMC value as specified in footnote (g) of Table (b)(1) of the California Toxics Rule, 2000. Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2018-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141764, Silver Region 2      Arroyo Mocho   LOE ID: 288003   Pollutant: Silver LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Silver. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The dissolved silver criterion maximum concentration (CMC) to protect aquatic life in freshwater is hardnesss dependent. The criterion when calculated using a default hardness of 100 mg/L is 3.4 ug/L. This criterion was divided by 2 in order to better represent a CMC value as specified in footnote (g) of Table (b)(1) of the California Toxics Rule, 2000. Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2018-05-16 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141764, Silver Region 2      Arroyo Mocho   LOE ID: 95371   Pollutant: Silver LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for arsenic, chromium VI, copper, lead, nickel, silver and zinc. Concentrations of total dissolved chromium were well below the objective for chromium VI. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Table 3-4 in the Basin Plan (2007) lists freshwater water quality objectives for toxic pollutants: arsenic- 150 ug/L, chromium VI- 11 ug/L, copper - 9.0 ug/L, lead - 2.5 ug/L; nickel - 52 ug/L, silver-3.4 ug/L and zinc - 120 ug/L. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed (above Vulcan Bridge Zone 7). Temporal Representation: Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005. Environmental Conditions: There were no unusual environmental conditions associated with the sampling. QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   n="top" colspan="2">Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141764, Silver Region 2      Arroyo Mocho
LOE ID:	288106
Pollutant:	Silver
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Silver.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved silver criterion maximum concentration (CMC) to protect aquatic life in freshwater is hardnesss dependent. The criterion when calculated using a default hardness of 100 mg/L is 3.4 ug/L. This criterion was divided by 2 in order to better represent a CMC value as specified in footnote (g) of Table (b)(1) of the California Toxics Rule, 2000.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141764, Silver Region 2      Arroyo Mocho
LOE ID:	288043
Pollutant:	Silver
LOE Subgroup:	Pol   DECISION ID 141766 Region 2      Arroyo Mocho   Pollutant: Thiobencarb/Bolero Final Listing Decision: Do Not List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: New Decision Revision Status Revised Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.   Listing Extent:     Line of Evidence (LOE) for Decision ID 141766, Thiobencarb/Bolero Region 2      Arroyo Mocho   LOE ID: 290100   Pollutant: Thiobencarb/Bolero LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for PCBs, Chlorpyrifos, Dacthal, diazinon, disulfoton, endosulfan, Lindane/gamma Hexachlorocyclohexane (gamma-HCH), methyl parathion, thiobencarb. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.Diazinon water quality objective, 0.1 ug/L (acute) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: PCBs - 0.014 ug/L freshwater continuous Concentration; Chlorpyrifos - 0.015 ug/L (chronic); Dacthal (DCPA) - 14300 ug/L (acute); Disulfoton (Disyston) - 0.05 ug/L (acute); Endosulfan - 0.056 ug/L (chronic)/0.22 ug/L (acute); HCH, gamma-(gamma BHC, Lindane) - 0.95 ug/L (acute); methyl parathion - 0.08 ug/L (acute); Thiobencarb - 3.1 ug/L (acute). Guideline Reference: National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA   Spatial Representation: Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed. Temporal Representation: Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   lutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Silver.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved silver criterion maximum concentration (CMC) to protect aquatic life in freshwater is hardnesss dependent. The criterion when calculated using a default hardness of 100 mg/L is 3.4 ug/L. This criterion was divided by 2 in order to better represent a CMC value as specified in footnote (g) of Table (b)(1) of the California Toxics Rule, 2000.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141764, Silver Region 2      Arroyo Mocho
LOE ID:	288003
Pollutant:	Silver
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Silver.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved silver criterion maximum concentration (CMC) to protect aquatic life in freshwater is hardnesss dependent. The criterion when calculated using a default hardness of 100 mg/L is 3.4 ug/L. This criterion was divided by 2 in order to better represent a CMC value as specified in footnote (g) of Table (b)(1) of the California Toxics Rule, 2000.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141764, Silver Region 2      Arroyo Mocho
LOE ID:	95371
Pollutant:	Silver
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for arsenic, chromium VI, copper, lead, nickel, silver and zinc. Concentrations of total dissolved chromium were well below the objective for chromium VI.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Table 3-4 in the Basin Plan (2007) lists freshwater water quality objectives for toxic pollutants: arsenic- 150 ug/L, chromium VI- 11 ug/L, copper - 9.0 ug/L, lead - 2.5 ug/L; nickel - 52 ug/L, silver-3.4 ug/L and zinc - 120 ug/L.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed (above Vulcan Bridge Zone 7).
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:	There were no unusual environmental conditions associated with the sampling.
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	141766	Region 2
Arroyo Mocho

Pollutant:	Thiobencarb/Bolero
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141766, Thiobencarb/Bolero Region 2      Arroyo Mocho
LOE ID:	290100
Pollutant:	Thiobencarb/Bolero
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for PCBs, Chlorpyrifos, Dacthal, diazinon, disulfoton, endosulfan, Lindane/gamma Hexachlorocyclohexane (gamma-HCH), methyl parathion, thiobencarb.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.Diazinon water quality objective, 0.1 ug/L (acute)
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	PCBs - 0.014 ug/L freshwater continuous Concentration; Chlorpyrifos - 0.015 ug/L (chronic); Dacthal (DCPA) - 14300 ug/L (acute); Disulfoton (Disyston) - 0.05 ug/L (acute); Endosulfan - 0.056 ug/L (chronic)/0.22 ug/L (acute); HCH, gamma-(gamma BHC, Lindane) - 0.95 ug/L (acute); methyl parathion - 0.08 ug/L (acute); Thiobencarb - 3.1 ug/L (acute).
Guideline Reference:	National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed.
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID	141768	Region 2
Arroyo Mocho

Pollutant:	Turbidity
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	289613
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTUs or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food. The application of this evaluation guideline was restricted to the dry season (May to October) because Coho and steelhead early life stages are present during the dry season and feeding becomes infrequent during the winter months (Moyle 2002). Additionally, runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Guideline Reference:	Inland Fishes of California
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence).
Temporal Representation:	The samples were collected between the dates of 2019-05-29 and 2019-08-27
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	289439
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTUs or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food. The application of this evaluation guideline was restricted to the dry season (May to October) because Coho and steelhead early life stages are present during the dry season and feeding becomes infrequent during the winter months (Moyle 2002). Additionally, runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Guideline Reference:	Inland Fishes of California
Spatial Representation:
DECISION ID	141768	Region 2
Arroyo Mocho

Pollutant:	Turbidity
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	289613
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTUs or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food. The application of this evaluation guideline was restricted to the dry season (May to October) because Coho and steelhead early life stages are present during the dry season and feeding becomes infrequent during the winter months (Moyle 2002). Additionally, runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Guideline Reference:	Inland Fishes of California
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence).
Temporal Representation:	The samples were collected between the dates of 2019-05-29 and 2019-08-27
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	289439
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTUs or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food. The application of this evaluation guideline was restricted to the dry season (May to October) because Coho and steelhead early life stages are present during the dry season and feeding becomes infrequent during the winter months (Moyle 2002). Additionally, runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Guideline Reference:	Inland Fishes of California
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2019-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	289441
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTUs or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food. The application of this evaluation guideline was restricted to the dry season (May to October) because Coho and steelhead early life stages are present during the dry season and feeding becomes infrequent during the winter months (Moyle 2002). Additionally, runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Guideline Reference:	Inland Fishes of California
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection).
Temporal Representation:	The samples were collected between the dates of 2019-05-07 and 2019-05-30
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho   LOE ID: 289441   Pollutant: Turbidity LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Turbidity. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Sigler et al. (1984) states that turbidities of 25 NTUs or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food. The application of this evaluation guideline was restricted to the dry season (May to October) because Coho and steelhead early life stages are present during the dry season and feeding becomes infrequent during the winter months (Moyle 2002). Additionally, runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis. Guideline Reference: Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150 Guideline Reference: Inland Fishes of California   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-05-07 and 2019-05-30 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho   LOE ID: 289603   Pollutant: Turbidity LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Turbidity. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Sigler et al. (1984) states that turbidities of 25 NTUs or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food. The application of this evaluation guideline was restricted to the dry season (May to October) because Coho and steelhead early life stages are present during the dry season and feeding becomes infrequent during the winter months (Moyle 2002). Additionally, runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis. Guideline Reference: Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150 Guideline Reference: Inland Fishes of California   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-06-04 and 2019-07-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho   LOE ID: 289501   Pollutant: Turbidity LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Region 2      Arroyo Mocho
LOE ID:	289603
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTUs or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food. The application of this evaluation guideline was restricted to the dry season (May to October) because Coho and steelhead early life stages are present during the dry season and feeding becomes infrequent during the winter months (Moyle 2002). Additionally, runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Guideline Reference:	Inland Fishes of California
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road).
Temporal Representation:	The samples were collected between the dates of 2019-06-04 and 2019-07-24
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	289501
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTUs or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food. The application of this evaluation guideline was restricted to the dry season (May to October) because Coho and steelhead early life stages are present during the dry season and feeding becomes infrequent during the winter months (Moyle 2002). Additionally, runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Guideline Reference:	Inland Fishes of California
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout).
Temporal Representation:	The samples were collected between the dates of 2019-05-09 and 2019-05-09
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	289374
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
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Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTUs or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food. The application of this evaluation guideline was restricted to the dry season (May to October) because Coho and steelhead early life stages are present during the dry season and feeding becomes infrequent during the winter months (Moyle 2002). Additionally, runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Guideline Reference:	Inland Fishes of California
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout).
Temporal Representation:	The samples were collected between the dates of 2019-05-09 and 2019-05-09
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	289374
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTUs or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food. The application of this evaluation guideline was restricted to the dry season (May to October) because Coho and steelhead early life stages are present during the dry season and feeding becomes infrequent during the winter months (Moyle 2002). Additionally, runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Guideline Reference:	Inland Fishes of California
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2018-05-14
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	289515
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTUs or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food. The application of this evaluation guideline was restricted to the dry season (May to October) because Coho and steelhead early life stages are present during the dry seasosp;
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTUs or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food. The application of this evaluation guideline was restricted to the dry season (May to October) because Coho and steelhead early life stages are present during the dry season and feeding becomes infrequent during the winter months (Moyle 2002). Additionally, runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Guideline Reference:	Inland Fishes of California
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2018-05-14
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	289515
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTUs or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food. The application of this evaluation guideline was restricted to the dry season (May to October) because Coho and steelhead early life stages are present during the dry season and feeding becomes infrequent during the winter months (Moyle 2002). Additionally, runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Guideline Reference:	Inland Fishes of California
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2019-06-05
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	289500
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 5 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTUs or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food. The application of this evaluation guideline was restricted to the dry season (May to October) because Coho and steelhead early life stages are present during the dry season and feeding becomes infrequent during the winter months (Moyle 2002). Additionally, runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Guideline Reference:	Inland Fishes of California
Spatial Representation:	The samples were collected at 1 monitoring site: 204TASS01 (n and feeding becomes infrequent during the winter months (Moyle 2002). Additionally, runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Guideline Reference:	Inland Fishes of California
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2019-06-05
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	289500
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 5 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTUs or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food. The application of this evaluation guideline was restricted to the dry season (May to October) because Coho and steelhead early life stages are present during the dry season and feeding becomes infrequent during the winter months (Moyle 2002). Additionally, runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Guideline Reference:	Inland Fishes of California
Spatial Representation:	The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence).
Temporal Representation:	The samples were collected between the dates of 2019-05-15 and 2019-08-27
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	302795
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009). The application of this evaluation guideline was restricted to the dry season (May to October) because runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
Spatial Representation:	The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence).
Temporal Representation:	The samples were collected between the dates of 2019-05-15 and 2019-08-27
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Temporal Representation: The samples were collected between the dates of 2019-05-15 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho   LOE ID: 302795   Pollutant: Turbidity LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 5 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Turbidity. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009). The application of this evaluation guideline was restricted to the dry season (May to October) because runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis. Guideline Reference: The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-05-15 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho   LOE ID: 302792   Pollutant: Turbidity LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Turbidity. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009). The application of this evaluation guideline was restricted to the dry season (May to October) because runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis. Guideline Reference: The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-05-07 and 2019-05-30 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho   LOE ID: 302753   Pollutant: Turbidity LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follG-RIGHT: 2%; PADDING-LEFT: 0%; FONT-WEIGHT: bold; PADDING-BOTTOM: 3px; WIDTH: 100%; text-align: left; PADDING-TOP: 3px; font-smooth: always">Arroyo Mocho
LOE ID:	302792
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009). The application of this evaluation guideline was restricted to the dry season (May to October) because runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection).
Temporal Representation:	The samples were collected between the dates of 2019-05-07 and 2019-05-30
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	302753
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009). The application of this evaluation guideline was restricted to the dry season (May to October) because runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road).
Temporal Representation:	The samples were collected between the dates of 2019-06-04 and 2019-07-24
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	302932
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009). The application of this evaluation guideline was restriows: 0 of 3 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009). The application of this evaluation guideline was restricted to the dry season (May to October) because runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road).
Temporal Representation:	The samples were collected between the dates of 2019-06-04 and 2019-07-24
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	302932
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009). The application of this evaluation guideline was restricted to the dry season (May to October) because runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2019-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	302796
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009). The application of this evaluation guideline was restricted to the dry season (May to October) because runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2019-06-05
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	Guideline Reference:	The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2019-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	302796
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009). The application of this evaluation guideline was restricted to the dry season (May to October) because runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2019-06-05
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	302684
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009). The application of this evaluation guideline was restricted to the dry season (May to October) because runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2019-08-26
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	302845
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	302684
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009). The application of this evaluation guideline was restricted to the dry season (May to October) because runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2019-08-26
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	302845
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009). The application of this evaluation guideline was restricted to the dry season (May to October) because runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence).
Temporal Representation:	The samples were collected between the dates of 2019-05-29 and 2019-08-27
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	302946
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable wat" valign="top" width="67%">Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009). The application of this evaluation guideline was restricted to the dry season (May to October) because runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence).
Temporal Representation:	The samples were collected between the dates of 2019-05-29 and 2019-08-27
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	302946
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009). The application of this evaluation guideline was restricted to the dry season (May to October) because runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout).
Temporal Representation:	The samples were collected between the dates of 2019-05-09 and 2019-05-09
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	302725
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009). The application of this evaluation guideline was restricted to the dry season (May to October) because runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	The Effects of Turbidity on Prey Selection by Piscivorous Largter quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009). The application of this evaluation guideline was restricted to the dry season (May to October) because runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout).
Temporal Representation:	The samples were collected between the dates of 2019-05-09 and 2019-05-09
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	302725
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009). The application of this evaluation guideline was restricted to the dry season (May to October) because runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2018-05-14
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141768, Turbidity Region 2      Arroyo Mocho
LOE ID:	289249
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Turbidity.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Sigler et al. (1984) states that turbidities of 25 NTUs or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food. The application of this evaluation guideline was restricted to the dry season (May to October) because Coho and steelhead early life stages are present during the dry season and feeding becomes infrequent during the winter months (Moyle 2002). Additionally, runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis.
Guideline Reference:	Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Guideline Reference:	Inland Fishes of California
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2019-08-26
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

emouth Bass   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 141768, Turbidity	Region 2
Arroyo Mocho

  LOE ID: 289249   Pollutant: Turbidity LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 5 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Turbidity. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Sigler et al. (1984) states that turbidities of 25 NTUs or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food. The application of this evaluation guideline was restricted to the dry season (May to October) because Coho and steelhead early life stages are present during the dry season and feeding becomes infrequent during the winter months (Moyle 2002). Additionally, runoff and resuspension of fine substrate during storm events may naturally elevate turbidity compared to baseflow conditions. The magnitude and duration of these increases will vary depending on the watershed’s geology and land use and may not represent a chronic turbidity problem. Turbidity is naturally higher in tidal river systems, so sample locations with salinity regimes (i.e., Freshwater or Marine) designated as “Marine” were excluded from this analysis. Guideline Reference: Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150 Guideline Reference: Inland Fishes of California   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-08-26 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

DECISION ID	141769	Region 2
Arroyo Mocho

Pollutant:	Zinc
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141769, Zinc Region 2      Arroyo Mocho
LOE ID:	95366
Pollutant:	Zinc
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of arsenic, cadmium, chromium, copper, lead, mercury and zinc in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) arsenic - 33 mg/kg dw; cadmium - 4.98 mg/kg dw; chromium - 111 mg/kg dw; copper - 149 mg/kg dw; lead - 128 mg/kg dw; mercury - 1.06 mg/kg dw; nickel - 48.6 mg/kg dw; zinc - 459 mg/kg dw.
Guideline Reference:
DECISION ID	141769	Region 2
Arroyo Mocho

Pollutant:	Zinc
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
Listing Extent:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Line of Evidence (LOE) for Decision ID 141769, Zinc Region 2      Arroyo Mocho
LOE ID:	95366
Pollutant:	Zinc
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Concentrations of arsenic, cadmium, chromium, copper, lead, mercury and zinc in one sediment sample collected in spring 2005 did not exceed the sediment quality guidelines.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment Quality Guidelines (MacDonald et al., 2000): PEC (probable effect concentration) arsenic - 33 mg/kg dw; cadmium - 4.98 mg/kg dw; chromium - 111 mg/kg dw; copper - 149 mg/kg dw; lead - 128 mg/kg dw; mercury - 1.06 mg/kg dw; nickel - 48.6 mg/kg dw; zinc - 459 mg/kg dw.
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	One sediment sample was collected at a "watershed integrator" site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:	There were no unusual environmental conditions associated with the sampling.
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141769, Zinc Region 2      Arroyo Mocho
LOE ID:	95372
Pollutant:	Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for arsenic, chromium VI, copper, lead, nickel, silver and zinc. Concentrations of total dissolved chromium were well below the objective for chromium VI.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Table 3-4 in the Basin Plan (2007) lists freshwater water quality objectives for toxic pollutants: arsenic- 150 ug/L, chromium VI- 11 ug/L, copper - 9.0 ug/L, lead - 2.5 ug/L; nickel - 52 ug/L, silver-3.4 ug/L and zinc - 120 ug/L.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed (above Vulcan Bridge Zone 7).
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:	There were no unusual environmental conditions associated with the sampling.
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141769, Zinc Region 2      Arroyo Mocho
Spatial Representation:	One sediment sample was collected at a "watershed integrator" site located close to the mouth of Arroyo Mocho watershed.
Temporal Representation:	Sediment sample was collected in April of 2005.
Environmental Conditions:	There were no unusual environmental conditions associated with the sampling.
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141769, Zinc Region 2      Arroyo Mocho
LOE ID:	95372
Pollutant:	Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	The Arroyo Mocho watershed was monitored as part of SWAMP assessment. None of the three samples exceeded the water quality objectives for arsenic, chromium VI, copper, lead, nickel, silver and zinc. Concentrations of total dissolved chromium were well below the objective for chromium VI.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. Table 3-4 in the Basin Plan (2007) lists freshwater water quality objectives for toxic pollutants: arsenic- 150 ug/L, chromium VI- 11 ug/L, copper - 9.0 ug/L, lead - 2.5 ug/L; nickel - 52 ug/L, silver-3.4 ug/L and zinc - 120 ug/L.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	Data were collected at one sampling location (AMO070) in the Arroyo Mocho watershed (above Vulcan Bridge Zone 7).
Temporal Representation:	Samples were collected during wet (January), spring (April), and dry( June) seasons of 2005.
Environmental Conditions:	There were no unusual environmental conditions associated with the sampling.
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141769, Zinc Region 2      Arroyo Mocho
LOE ID:	276245
Pollutant:	Zinc
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Zinc .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for zinc is the probable effect concentration (PEC) of 459 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141769, Zinc Region 2      Arroyo Mocho
LOE ID:	276232
Pollutant:	Zinc
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Zinc .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other det>
LOE ID:	276245
Pollutant:	Zinc
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Zinc .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for zinc is the probable effect concentration (PEC) of 459 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141769, Zinc Region 2      Arroyo Mocho
LOE ID:	276232
Pollutant:	Zinc
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Zinc .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for zinc is the probable effect concentration (PEC) of 459 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141769, Zinc Region 2      Arroyo Mocho
LOE ID:	289889
Pollutant:	Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Zinc.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved zinc criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 120 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141769, Zinc Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for zinc is the probable effect concentration (PEC) of 459 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: Data for this waterbody were collected over the date range 2012-07-25 to 2012-07-25 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 141769, Zinc Region 2      Arroyo Mocho   LOE ID: 289889   Pollutant: Zinc LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Zinc. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The dissolved zinc criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 120 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2018-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141769, Zinc Region 2      Arroyo Mocho   LOE ID: 289827   Pollutant: Zinc LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Zinc. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The dissolved zinc criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 120 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2018-05-16 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 141769, Zinc Region 2      Arroyo Mocho   LOE ID: 289888   Pollutant: Zinc LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Zinc. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The dissolved zinc criterion continuous concentration (exppx; font-smooth: always">Region 2      Arroyo Mocho
LOE ID:	289827
Pollutant:	Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Zinc.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved zinc criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 120 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141769, Zinc Region 2      Arroyo Mocho
LOE ID:	289888
Pollutant:	Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Zinc.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved zinc criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 120 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2018-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141769, Zinc Region 2      Arroyo Mocho
LOE ID:	276149
Pollutant:	Zinc
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Zinc .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for zinc is the probable effect concentration (PEC) of 459 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141769, Zinc Region 2      Arroyo Mocho
LOE ID:	289768
Pollutant:	Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Zinc.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The dissolved zinc criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 120 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2018-05-16
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141769, Zinc Region 2      Arroyo Mocho
LOE ID:	276463
Pollutant:	Zinc
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Zinc .
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The evaluation guideline for zinc is the probable effect concentration (PEC) of 459 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference:	Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
Spatial Representation:	Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

ressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 120 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2018-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 141769, Zinc	Region 2
Arroyo Mocho

  LOE ID: 276149   Pollutant: Zinc LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Zinc . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for zinc is the probable effect concentration (PEC) of 459 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 141769, Zinc	Region 2
Arroyo Mocho

  LOE ID: 289768   Pollutant: Zinc LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Zinc. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The dissolved zinc criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 120 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2018-05-16 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 141769, Zinc	Region 2
Arroyo Mocho

  LOE ID: 276463   Pollutant: Zinc LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Zinc . Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The evaluation guideline for zinc is the probable effect concentration (PEC) of 459 mg/kg dry weight (MacDonald et al., 2000a). Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31   Spatial Representation: Data were collected from 1 station(s). Station Code(s): 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: Data for this waterbody were collected over the date range 2014-07-23 to 2014-07-23 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

DECISION ID	154212	Region 2
Arroyo Mocho

Pollutant:	Benthic Community Effects
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	For the 2024 Integrated Report, USEPA disapproved 44 benthic community effects decisions that were placed in Category 3. The data and information demonstrated that the biological community is degraded, and the waterbody is listed on the 303(d) list with at least one pollutant impairment affecting an aquatic life beneficial use. This was an interim approach used to provide time to develop the methodology to associate the pollutant as a potential cause of the degraded biology. The USEPA reviewed the appropriateness of these category placements and indicated that the most appropriate classification for these 44 waterbody-pollutant combinations is Category 5. This decision was updated to reflect direction from USEPA. Benthic Community Effects are being considered for placement on the CWA section 303(d) List under sections 3.9 of the Listing Policy. Under section 3.9, additional lines of evidence (LOEs) associating the Benthic Community Effects decision with a water or sediment concentration of pollutants other than benthic-macroinvertebrate bioassessment or habitat assessment LOEs are necessary to place a water body on the 303(d) List for Benthic Community Effects. Twenty-three line(s) of evidence evaluating benthic-macroinvertebrate bioassessment data is/are available in the administrative record to assess this indicator. Twenty-one of 23 benthic-macroinvertebrate samples exceed the California Stream Condition Index (CSCI) impairment threshold. Additionally, there are associated pollutant impairments on the waterbody (including but not necessarily limited to Toxicity, Temperature, and pH). Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for placing Benthic Community Effects in this waterbody segment on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 21 of 23 benthic-macroinvertebrate bioassessment samples had CSCI scores below 0.79. Therefore, this water body is exceeding the water quality threshold for the protection of the WARM and/or COLD beneficial use. 4. Pursuant to section 3.9 of the Listing Policy, the water segment has associated pollutant(s) samples that exceed water quality objectives. 5. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	288451
Pollutant:	Temperature, water
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Not Recorded
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Temperature.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.”
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C.
Guideline Reference:	Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C
Guideline Reference:	Inland Fishes of California
Guideline Reference:	Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)).
Temporal Representation:	The samples were collected between the dates of 2019-04-02 and 2019-04-24
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	4789
Pollutant:	Temperature, water
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Aquatic Life Use:	Wildlife Habitat
Number of Samples:	12
Number of Exceedances:	6
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Comprehensive water quality assessment was conducted at the Arroyo Mocho watershed as part of SWAMP assessment. Continuous field monitoring at 15 minute increments of temperature, dissolved oxygen, pH and specific conductance was conducted to determine temporal variability in basic water quality at five locations throughout the watershed. The measured temperatures ranged from 6.1°C to 27.72 °C and varied with season and location. The 17 °C criterion for steelhead was exceeded in 6 out of 12 deployments. High water temperatures exceeding 24 °C, that is a maximum short exposure temperature for survival of salmonids (EPA 1977) were also measured at three monitoring locations at lower and upper reaches of the Creek during spring and summer seasons. At the monitoring site in the lower reach of the Arroyo Mocho Creek high temperature persisted for up to 5.75 hours during spring while at the middle and upper reach it lasted from 5 to more than 9 hours.
Data Reference:	Water Quality Monitoring and Bioassessment in Nine San Francisco Bay Region Watersheds: Walker Creek, Lagunitas Creek, San Leandro Creek, Wildcat Creek/San Pablo Creek, Suisun Creek, Arroyo Las Positas, Pescadero Creek/Butano Creek, San Gregorio Creek, and Stevens Creek/Permanente Creek. Oakland, CA: Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Temperature objectives for enclosed bays and estuaries are specified in the "Water Quality Control Plan for Control of Temperature in the Coastal and Interstate Waters and Enclosed Bays of California" including any revisions to the plan. In addition, the following temperature objectives apply to surface waters: The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sullivan et al. (2000) reviewed a wide range of studies incorporating information from laboratory-based research, field observations, and risk assessment approaches and developed criteria for assessing temperature risk to aquatic life. The 7-day mean temperature (maximum value of the 7-day moving average of the daily mean temperature) of 14.8°C was established as the upper threshold criterion for coho salmon and 17.0°C for steelhead trout. The risk assessment approach used by Sullivan et al. (2000) suggests that temperatures exceeding the above thresholds will cause 10% reduction in average fish growth compared to optimal conditions.
Guideline Reference:	An Analysis of the Effects of Temperature on Salmonids of the Pacific Northwest with Implications for Selecting Temperature Criteria
Spatial Representation:	Temperature was measured at five sites located on the mainstem of Arroyo Mocho Creek. The highest temperatures were recorded at the monitoring location southeast of Livermore in August 2004. High temperatures also occurred in the lower reach of the Creek during the spring season of 2004.
Temporal Representation:	In 2004 and 2005 the SWAMP Program performed continuous monitoring of temperature at 15 minute intervals for periods of 1-2 weeks in each of three different seasons: winter (5 sites), spring (5 sites), and summer dry season (2 sites).
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	289059
Pollutant:	Temperature, water
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Not Recorded
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Temperature.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.”
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C.
Guideline Reference:	Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C
Guideline Reference:	Inland Fishes of California
Guideline Reference:	Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd).
Temporal Representation:	The samples were collected between the dates of 2017-06-12 and 2017-06-12
Environmental Conditions:
QAPP Information:	EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s):	BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	288444
Pollutant:	Temperature, water
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Not Recorded
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	6
Number of Exceedances:	5
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 5 of 6 samples exceeded the water quality threshold for Temperature.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.”
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C.
Guideline Reference:	Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C
Guideline Reference:	Inland Fishes of California
Guideline Reference:	Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-08-27
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	289107
Pollutant:	Temperature, water
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Not Recorded
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	12
Number of Exceedances:	3
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 3 of 12 samples exceeded the water quality threshold for Temperature.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.”
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C.
Guideline Reference:	Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C
Guideline Reference:	Inland Fishes of California
Guideline Reference:	Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2019-08-26
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	289003
Pollutant:	Temperature, water
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Not Recorded
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 4 samples exceeded the water quality threshold for Temperature.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.”
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C.
Guideline Reference:	Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C
Guideline Reference:	Inland Fishes of California
Guideline Reference:	Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-05-30
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	268608
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	1 of the 2 samples collected by BASMAA RMC Monitoring in WY2014 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Ceriodaphnia dubia for Survival, Selenastrum capricornutum for Total Cell Count, Pimephales promelas for Survival, Pimephales promelas for Biomass (wt/orig indiv), Ceriodaphnia dubia for Young/female, Hyalella azteca for Survival. The following tests exhibited toxicity: Selenastrum capricornutum for Total Cell Count on 2014-07-23.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00292 ( Arroyo Mocho just upstream of confluence with Arroyo de la Laguna ).
Temporal Representation:	The samples were collected between the dates of 2014-03-29 and 2014-07-23.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	28994
Pollutant:	Toxicity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	1
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	Three samples were collected in 2005 to evaluate water toxicity at two monitoring locations in Arroyo Mocho watershed. The toxicity tests included survival and reproduction of Ceriodaphnia, survival and growth of fathead minnow, and growth of Selenastrum. Ceriodaphnia growth was significantly lower than the control in one of three samples (dry season sample). Growth was 69.4 percent of the control for this sample.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Water toxicity was evaluated according to the SWAMP methodology. The U.S.EPA whole effluent toxicity protocol (U.S.EPA 1994) was used to test the effect of water samples on three freshwater test organisms. Statistical evaluation (alpha = 0.05) and a default threshold of 80% of the control value were used to establish whether water exhibited significant toxicity adversely impacting aquatic organisms.
Guideline Reference:	Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. EPA/600/4-91/002. Third Edition. July 1994
Guideline Reference:	Revised approach to toxicity test acceptability criteria using a statistical performance assessment. Environmental Toxicology and Chemistry, vol. 16, No. 6, pp 1322¿1329
Spatial Representation:	Data were collected at one sampling location, AMO070, located above Vulcan Bridge Zone 7, representing the Arroyo Mocho Creek.
Temporal Representation:	SWAMP samples were collected during wet (January), spring (April), and dry (June) seasons of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	268610
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	1 of the 2 samples collected by BASMAA RMC Monitoring in WY2012 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Pimephales promelas for Biomass (wt/orig indiv), Selenastrum capricornutum for Total Cell Count, Ceriodaphnia dubia for Young/female, Ceriodaphnia dubia for Survival, Pimephales promelas for Survival, Hyalella azteca for Survival. The following tests exhibited toxicity: Pimephales promelas for Survival on 2012-03-14.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00100 ( Arroyo Mocho_BA_2012-204R00100 ).
Temporal Representation:	The samples were collected between the dates of 2012-03-14 and 2012-07-25.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	283026
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorophyll a.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout).
Temporal Representation:	The samples were collected between the dates of 2019-05-09 and 2019-05-09
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	283081
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorophyll a.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection).
Temporal Representation:	The samples were collected between the dates of 2019-05-07 and 2019-05-07
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	282995
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Chlorophyll a.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2019-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	282868
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorophyll a.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence).
Temporal Representation:	The samples were collected between the dates of 2019-05-15 and 2019-05-15
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	286760
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2019-06-05
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	287331
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	5
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 5 of 7 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-08-27
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	306684
Pollutant:	Benthic-Macroinvertebrate Bioassessments
LOE Subgroup:	Population/Community Degradation
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Water Board staff assessed data for 204AMO130 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.786844329 to 0.786844329.
Data Reference:	California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.Â
Guideline Reference:	Bioassessment in complex environments: designing an index for consistent meaning in different settings
Spatial Representation:	Samples were collected from station 204AMO130.
Temporal Representation:	Samples were collected from 5/9/2019 to 5/9/2019.
Environmental Conditions:
QAPP Information:	Data were collected using Surface Water Ambient Monitoring Program protocols
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	306622
Pollutant:	Benthic-Macroinvertebrate Bioassessments
LOE Subgroup:	Population/Community Degradation
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Water Board staff assessed data for 204AMO070 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.315975 to 0.315975.
Data Reference:	California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.Â
Guideline Reference:	Bioassessment in complex environments: designing an index for consistent meaning in different settings
Spatial Representation:	Samples were collected from station 204AMO070.
Temporal Representation:	Samples were collected from 4/12/2005 to 4/12/2005.
Environmental Conditions:
QAPP Information:	Data were collected using Surface Water Ambient Monitoring Program protocols
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	306647
Pollutant:	Benthic-Macroinvertebrate Bioassessments
LOE Subgroup:	Population/Community Degradation
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	2
Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Water Board staff assessed data for 204AMO140 to determine beneficial use support and the results are as follows: 2 of 2 samples exceeded the threshold. CSCI scores were from 0.558045193 to 0.628004285.
Data Reference:	California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.Â
Guideline Reference:	Bioassessment in complex environments: designing an index for consistent meaning in different settings
Spatial Representation:	Samples were collected from station 204AMO140.
Temporal Representation:	Samples were collected from 5/8/2018 to 5/8/2019.
Environmental Conditions:
QAPP Information:	Data were collected using Surface Water Ambient Monitoring Program protocols
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	306671
Pollutant:	Benthic-Macroinvertebrate Bioassessments
LOE Subgroup:	Population/Community Degradation
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Water Board staff assessed data for 204R01828 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.272188 to 0.272188.
Data Reference:	California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.Â
Guideline Reference:	Bioassessment in complex environments: designing an index for consistent meaning in different settings
Spatial Representation:	Samples were collected from station 204R01828.
Temporal Representation:	Samples were collected from 5/20/2015 to 5/20/2015.
Environmental Conditions:
QAPP Information:	Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	306623
Pollutant:	Benthic-Macroinvertebrate Bioassessments
LOE Subgroup:	Population/Community Degradation
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Water Board staff assessed data for 204AMO100 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.670381 to 0.670381.
Data Reference:	California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.Â
Guideline Reference:	Bioassessment in complex environments: designing an index for consistent meaning in different settings
Spatial Representation:	Samples were collected from station 204AMO100.
Temporal Representation:	Samples were collected from 4/12/2005 to 4/12/2005.
Environmental Conditions:
QAPP Information:	Data were collected using Surface Water Ambient Monitoring Program protocols
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	306683
Pollutant:	Benthic-Macroinvertebrate Bioassessments
LOE Subgroup:	Population/Community Degradation
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Water Board staff assessed data for 204AMO165 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.747701078 to 0.747701078.
Data Reference:	California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.Â
Guideline Reference:	Bioassessment in complex environments: designing an index for consistent meaning in different settings
Spatial Representation:	Samples were collected from station 204AMO165.
Temporal Representation:	Samples were collected from 5/7/2019 to 5/7/2019.
Environmental Conditions:
QAPP Information:	Data were collected using Surface Water Ambient Monitoring Program protocols
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	306658
Pollutant:	Benthic-Macroinvertebrate Bioassessments
LOE Subgroup:	Population/Community Degradation
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Water Board staff assessed data for 204TASS01 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.280629323 to 0.280629323.
Data Reference:	California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.Â
Guideline Reference:	Bioassessment in complex environments: designing an index for consistent meaning in different settings
Spatial Representation:	Samples were collected from station 204TASS01.
Temporal Representation:	Samples were collected from 5/15/2019 to 5/15/2019.
Environmental Conditions:
QAPP Information:	Data were collected using Surface Water Ambient Monitoring Program protocols
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	306636
Pollutant:	Benthic-Macroinvertebrate Bioassessments
LOE Subgroup:	Population/Community Degradation
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Water Board staff assessed data for 204R00473 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.676338 to 0.676338.
Data Reference:	California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.Â
Guideline Reference:	Bioassessment in complex environments: designing an index for consistent meaning in different settings
Spatial Representation:	Samples were collected from station 204R00473.
Temporal Representation:	Samples were collected from 5/9/2013 to 5/9/2013.
Environmental Conditions:
QAPP Information:	Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	306646
Pollutant:	Benthic-Macroinvertebrate Bioassessments
LOE Subgroup:	Population/Community Degradation
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Water Board staff assessed data for 204R01471 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.224225 to 0.224225.
Data Reference:	California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.Â
Guideline Reference:	Bioassessment in complex environments: designing an index for consistent meaning in different settings
Spatial Representation:	Samples were collected from station 204R01471.
Temporal Representation:	Samples were collected from 5/22/2013 to 5/22/2013.
Environmental Conditions:
QAPP Information:	Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	306612
Pollutant:	Benthic-Macroinvertebrate Bioassessments
LOE Subgroup:	Population/Community Degradation
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Water Board staff assessed data for 204AMO200 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.585441 to 0.585441.
Data Reference:	California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.Â
Guideline Reference:	Bioassessment in complex environments: designing an index for consistent meaning in different settings
Spatial Representation:	Samples were collected from station 204AMO200.
Temporal Representation:	Samples were collected from 4/11/2005 to 4/11/2005.
Environmental Conditions:
QAPP Information:	Data were collected using Surface Water Ambient Monitoring Program protocols
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	306611
Pollutant:	Benthic-Macroinvertebrate Bioassessments
LOE Subgroup:	Population/Community Degradation
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	1
Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Water Board staff assessed data for 204AMO180 to determine beneficial use support and the results are as follows: 1 of 3 samples exceeded the threshold. CSCI scores were from 0.673506667 to 0.937994.
Data Reference:	California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.Â
Guideline Reference:	Bioassessment in complex environments: designing an index for consistent meaning in different settings
Spatial Representation:	Samples were collected from station 204AMO180.
Temporal Representation:	Samples were collected from 4/11/2005 to 6/5/2019.
Environmental Conditions:
QAPP Information:	Data were collected using Surface Water Ambient Monitoring Program protocols
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	306634
Pollutant:	Benthic-Macroinvertebrate Bioassessments
LOE Subgroup:	Population/Community Degradation
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Water Board staff assessed data for 204PS0094 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.344929642 to 0.344929642.
Data Reference:	California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.Â
Guideline Reference:	Bioassessment in complex environments: designing an index for consistent meaning in different settings
Spatial Representation:	Samples were collected from station 204PS0094.
Temporal Representation:	Samples were collected from 7/14/2010 to 7/14/2010.
Environmental Conditions:
QAPP Information:	Data were collected using Surface Water Ambient Monitoring Program protocols
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	306635
Pollutant:	Benthic-Macroinvertebrate Bioassessments
LOE Subgroup:	Population/Community Degradation
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Water Board staff assessed data for 204R00100 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.339744 to 0.339744.
Data Reference:	California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.Â
Guideline Reference:	Bioassessment in complex environments: designing an index for consistent meaning in different settings
Spatial Representation:	Samples were collected from station 204R00100.
Temporal Representation:	Samples were collected from 5/30/2012 to 5/30/2012.
Environmental Conditions:
QAPP Information:	Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	306682
Pollutant:	Benthic-Macroinvertebrate Bioassessments
LOE Subgroup:	Population/Community Degradation
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	2
Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Water Board staff assessed data for 204ALP020 to determine beneficial use support and the results are as follows: 2 of 2 samples exceeded the threshold. CSCI scores were from 0.604082263 to 0.661446763.
Data Reference:	California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.Â
Guideline Reference:	Bioassessment in complex environments: designing an index for consistent meaning in different settings
Spatial Representation:	Samples were collected from station 204ALP020.
Temporal Representation:	Samples were collected from 5/16/2018 to 6/13/2019.
Environmental Conditions:
QAPP Information:	Data were collected using Surface Water Ambient Monitoring Program protocols
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	306648
Pollutant:	Benthic-Macroinvertebrate Bioassessments
LOE Subgroup:	Population/Community Degradation
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Water Board staff assessed data for 204AMO195 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.645766977 to 0.645766977.
Data Reference:	California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.Â
Guideline Reference:	Bioassessment in complex environments: designing an index for consistent meaning in different settings
Spatial Representation:	Samples were collected from station 204AMO195.
Temporal Representation:	Samples were collected from 5/14/2018 to 5/14/2018.
Environmental Conditions:
QAPP Information:	Data were collected using Surface Water Ambient Monitoring Program protocols
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	306659
Pollutant:	Benthic-Macroinvertebrate Bioassessments
LOE Subgroup:	Population/Community Degradation
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Water Board staff assessed data for 204AMO190 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.595075868 to 0.595075868.
Data Reference:	California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.Â
Guideline Reference:	Bioassessment in complex environments: designing an index for consistent meaning in different settings
Spatial Representation:	Samples were collected from station 204AMO190.
Temporal Representation:	Samples were collected from 6/4/2019 to 6/4/2019.
Environmental Conditions:
QAPP Information:	Data were collected using Surface Water Ambient Monitoring Program protocols
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	306624
Pollutant:	Benthic-Macroinvertebrate Bioassessments
LOE Subgroup:	Population/Community Degradation
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Water Board staff assessed data for 204AMO160 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.621941 to 0.621941.
Data Reference:	California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.Â
Guideline Reference:	Bioassessment in complex environments: designing an index for consistent meaning in different settings
Spatial Representation:	Samples were collected from station 204AMO160.
Temporal Representation:	Samples were collected from 4/12/2005 to 4/12/2005.
Environmental Conditions:
QAPP Information:	Data were collected using Surface Water Ambient Monitoring Program protocols
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	306672
Pollutant:	Benthic-Macroinvertebrate Bioassessments
LOE Subgroup:	Population/Community Degradation
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Water Board staff assessed data for 204R01497 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.55806279 to 0.55806279.
Data Reference:	California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.Â
Guideline Reference:	Bioassessment in complex environments: designing an index for consistent meaning in different settings
Spatial Representation:	Samples were collected from station 204R01497.
Temporal Representation:	Samples were collected from 6/12/2017 to 6/12/2017.
Environmental Conditions:
QAPP Information:	Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	306670
Pollutant:	Benthic-Macroinvertebrate Bioassessments
LOE Subgroup:	Population/Community Degradation
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	Benthic macroinvertebrate surveys
Data Used to Assess Water Quality:	Water Board staff assessed data for 204R00292 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.233503 to 0.233503.
Data Reference:	California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.Â
Guideline Reference:	Bioassessment in complex environments: designing an index for consistent meaning in different settings
Spatial Representation:	Samples were collected from station 204R00292.
Temporal Representation:	Samples were collected from 5/7/2014 to 5/7/2014.
Environmental Conditions:
QAPP Information:	Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho
LOE ID:	288744
Pollutant:	Temperature, water
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Not Recorded
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	5
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 5 of 7 samples exceeded the water quality threshold for Temperature.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.”
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C.
Guideline Reference:	Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C
Guideline Reference:	Inland Fishes of California
Guideline Reference:	Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region
Spatial Representation:	The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-08-27
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

DECISION ID	154554	Region 2
Arroyo Mocho

Pollutant:	Eutrophication
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for listing under sections 3.7.1 and 3.11 of the Listing Policy. Under section 3.7.1, an acceptable nutrient-related evaluation guideline is exceeded using the binomial distribution as described in section 3.1 for excessive algae growth, unnatural foam, odor, and taste. Waters may also be placed on the section 303(d) list when a significant nuisance condition exists as compared to reference conditions, or when nutrient concentrations cause or contribute to excessive algae growth. Under section 3.11, water segments shall be evaluated to determine whether the weight of evidence demonstrates that a water quality standard is not attained. When making a listing decision based on the situation-specific weight of evidence, the Regional Water Board must justify its recommendation by: 1. Providing any data or information including current conditions supporting the decision; 2. Describing in fact sheets how the data or information affords a substantial basis in fact from which the decision can be reasonably inferred; 3. Demonstrating that the weight of evidence of the data and information indicate that the water quality standard is not attained; and 4. Demonstrating that the approach used is scientifically defensible and reproducible. Eighty-three lines of evidence are available in the administrative record to assess these pollutants: (1) algae; (2) nitrogen; (3) nitrogen, nitrate; (4) total ammonia; (5) phosphorus; (6) chlorophyll-a (water column); (7) chlorophyll-a (benthic); (8) dissolved oxygen; and (9) pH. Based on the readily available data for this water body, the weight of evidence indicates that there is sufficient justification available in favor of adding this water segment-pollutant combination to the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used were collected by SWAMP and SWAMP-comparable programs which satisfy the data quality requirements of section 6.1.4 of the Policy. Sampling occurred at 20 sites between 2012-2019, so data are both spatially and temporally representative. Data were collected between April and August, so different stages of algal growth are represented in the dataset. 2. The evaluation of eutrophic conditions requires the weight of evidence approach because the evaluation process examining a stream’s trophic status requires measuring naturally occurring stream organisms (i.e., algae) and determining if the current amount of algae is affecting recreational beneficial uses or water quality parameters that influence aquatic life (e.g., pH and dissolved oxygen). Such an analysis requires the integration of secondary water quality indicators at sites with high algal biomass because the presence of algae alone does not demonstrate that aquatic impacts have occurred. For the lines of evidence regarding nutrients with direct toxic effects (e.g., un-ionized ammonia, total ammonia, and nitrate), Listing Policy Table 3.1 criteria for toxicants was used to determine if that aquatic life beneficial uses were affected by nutrient toxicity. 3. Nutrient-related evaluation guidelines for percent algae cover, total nitrogen, nitrate, and phosphorus were evaluated using the binomial distribution as described in section 3.1 of the Listing Policy. Five of 13 algae sampled exceeded the evaluation guideline of 30% cover and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. Four of 17 total nitrogen samples exceeded the evaluation guideline of 0.736 mg/L and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. Sixteen of 27 total phosphorus samples exceeded the evaluation guideline of 0.107 mg/L and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. The conventional parameters chlorophyll, dissolved oxygen, and pH were evaluated against binomial distribution tables as described in section 3.2 of the Listing Policy Four of 11 chlorophyll-a (water column) samples exceed the evaluation guideline of 40 ug/L and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. Six of 14 chlorophyll-a (benthic) samples exceed the evaluation guideline of 100 mg/m2 and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. Eighty-three of 202 days exceeded the dissolved oxygen evaluation guideline of 13 mg/L and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. Nineteen of 51 pH samples exceeded the evaluation guideline of 8.5 pH units and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. In addition to the aforementioned LOEs, continuous monitoring data showed daily dissolved oxygen swings greater than 5 mg/L for 106 of 202 days monitored, which is indicative of eutrophic conditions. There was generally strong agreement between indicators, meaning that sites exceeding evaluation guidelines for nutrients tended to show signs of nuisance algae growth or adverse effects to beneficial uses. 4. This process is scientifically defensible and reproducible. Data used to make this decision were collected using standardized SWAMP protocols and evaluated against U.S. EPA criteria, Basin Plan Water Quality Objectives, and technical report recommendations, when possible. When formal numeric objectives were not available, numeric evaluation guidelines were established using a reference-site approach (i.e., sites that are unimpacted or minimally impacted by humans) which was adapted from the U.S. EPA Nutrient Criteria Technical Guidance Manual. Reference status for nutrient and bioassessment sampling sites throughout the San Francisco Bay region were determined according to the method described by Ode et al. (2015).
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
State Board Review of Regional Board Conclusion and Recommendation:	The conventional parameters chlorophyll, dissolved oxygen, and pH were evaluated against binomial distribution tables as described in section 3.2 of the Listing Policy Four of 11 chlorophyll-a (water column) samples exceed the evaluation guideline of 40 ug/L and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. Six of 14 chlorophyll-a (benthic) samples exceed the evaluation guideline of 100 mg/m2 and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. Eighty-three of 202 days exceeded the dissolved oxygen evaluation guideline of 13 mg/L and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. Nineteen of 51 pH samples exceeded the evaluation guideline of 8.5 pH units and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. In addition to the aforementioned LOEs, continuous monitoring data showed daily dissolved oxygen swings greater than 5 mg/L for 106 of 202 days monitored, which is indicative of eutrophic conditions. There was generally strong agreement between indicators, meaning that sites exceeding evaluation guidelines for nutrients tended to show signs of nuisance algae growth or adverse effects to beneficial uses. 4. This process is scientifically defensible and reproducible. Data used to make this decision were collected using standardized SWAMP protocols and evaluated against U.S. EPA criteria, Basin Plan Water Quality Objectives, and technical report recommendations, when possible. When formal numeric objectives were not available, numeric evaluation guidelines were established using a reference-site approach (i.e., sites that are unimpacted or minimally impacted by humans) which was adapted from the U.S. EPA Nutrient Criteria Technical Guidance Manual. Reference status for nutrient and bioassessment sampling sites throughout the San Francisco Bay region were determined according to the method described by Ode et al. (2015).
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	315692
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Not Recorded
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	9
Number of Exceedances:	5
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC WY2012, WY2013, WY2014, WY2015, WY2017 and WY2019 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 5 of 9 samples exceeded the benthic chlorophyll evaluation guideline of 100 mg/m2.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
	Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Chapter 3.3.3 of the Water Quality Control Plan for the San Francisco Bay Basin states "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. Changes in chlorophyll a and associated phytoplankton communities follow complex dynamics that are sometimes associated with a discharge of biostimulatory substances. Irregular and extreme levels of chlorophyll a or phytoplankton blooms may indicate exceedance of this objective and require investigation."
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Creager et al. (2006) recommends an evaluation guideline of 100 mg/m2 for benthic chlorophyll-a. This guideline represents the Beneficial Use Risk Classification I/II (BURC I/II) boundary, which is a threshold below which nutrients do not present a significant risk of impairment as described in the Technical Approach to Develop Nutrient Numeric Endpoints for California.
Guideline Reference:	Technical Approach to Develop Nutrient Numeric Endpoints for California. U.S. EPA Region IX. State Water Resources Control Board. 68-C-02-108-To-111
Spatial Representation:	Data were collected from 9 station(s). Station Code(s): 204R01023, 204R00292, 204R01828, 204R01241, 204R01497, 204R04251, 204R00100, 204R01471, and 204R00473.
Temporal Representation:	Data for this waterbody were collected over the date range 2012-05-30 to 2019-06-17
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	315693
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Not Recorded
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP Monitoring in WY2018 and WY2019 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 1 of 5 samples exceeded the benthic chlorophyll evaluation guideline of 100 mg/m2.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Chapter 3.3.3 of the Water Quality Control Plan for the San Francisco Bay Basin states "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. Changes in chlorophyll a and associated phytoplankton communities follow complex dynamics that are sometimes associated with a discharge of biostimulatory substances. Irregular and extreme levels of chlorophyll a or phytoplankton blooms may indicate exceedance of this objective and require investigation."
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Creager et al. (2006) recommends an evaluation guideline of 100 mg/m2 for benthic chlorophyll-a. This guideline represents the Beneficial Use Risk Classification I/II (BURC I/II) boundary, which is a threshold below which nutrients do not present a significant risk of impairment as described in the Technical Approach to Develop Nutrient Numeric Endpoints for California.
Guideline Reference:	Technical Approach to Develop Nutrient Numeric Endpoints for California. U.S. EPA Region IX. State Water Resources Control Board. 68-C-02-108-To-111
Spatial Representation:	Data were collected from 3 station(s). Station Code(s): 204AMO140, 204AMO180, and 204AMO190
Temporal Representation:	Data for this waterbody were collected over the date range 2018-05-08 to 2019-06-05
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (2017).
QAPP Information Reference(s):	Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	286758
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd).
Temporal Representation:	The samples were collected between the dates of 2019-04-30 and 2019-04-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	286746
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-07-24
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	286901
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd).
Temporal Representation:	The samples were collected between the dates of 2019-06-17 and 2019-06-17
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	286988
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	The samples were collected between the dates of 2012-05-30 and 2012-05-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	315686
Pollutant:	Algae
LOE Subgroup:	Pollutant-Nuisance
Matrix:	Water
Fraction:	Percent
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	13
Number of Exceedances:	5
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	To estimate percent algae cover, SWAMP staff established a 50 m section that is representative of the stream reach. The 50 m section was divided into 5 m longitudinal transects and visually estimated the percent cover of filamentous green algae in 10% bins. The average of the ten transects was calculated to get an overall percent cover for each site. Sites were visited monthly to calculate changes across the dry season. To ensure consistency, the same field crew member conducted the estimates for the entire project.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Chapter 3.3.3 of the Water Quality Control Plan for the San Francisco Bay Basin states "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. Changes in chlorophyll a and associated phytoplankton communities follow complex dynamics that are sometimes associated with a discharge of biostimulatory substances. Irregular and extreme levels of chlorophyll a or phytoplankton blooms may indicate exceedance of this objective and require investigation."
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Biggs (2000) recommends a 30 percent cover by filamentous green or brown algae as a threshold associated with benthic chlorophyll-a levels consistent with protection of recreation and fisheries
Guideline Reference:	New Zealand Periphyton Guideline: Detecting Monitoring and Managing Enrichment of Streams
Spatial Representation:	Data were collected from 6 station(s). Station Code(s): 204AMO030, 204AMO100, 204AMO165, 204AMO190.
Temporal Representation:	Data were collected monthly from April-August 2019, which is representative of the algae growth period in the watershed.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (2017).
QAPP Information Reference(s):	Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	315683
Pollutant:	Phosphorus
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	18
Number of Exceedances:	16
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Sixteen of 18 samples had total phosphorus concentrations above 0.107 mg/L, which represents the 90th percentile of phosphorus concentrations at reference sites (i.e., minimally impacted sites) in San Francisco Bay Region.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Chapter 3.3.3 of the Water Quality Control Plan for the San Francisco Bay Basin states "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. Changes in chlorophyll a and associated phytoplankton communities follow complex dynamics that are sometimes associated with a discharge of biostimulatory substances. Irregular and extreme levels of chlorophyll a or phytoplankton blooms may indicate exceedance of this objective and require investigation."
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The 90th percentile of phosphorus concentrations in San Francisco Bay Region reference streams, 0.107 mg/L, was selected as the evaluation guideline, meaning ninety percent of reference sites will have concentrations at or below 0.107 mg/L for phosphorus. Currently, there are no numeric Water Quality Objectives or U.S. EPA criteria for algae-based indicators to determine if a water’s beneficial uses are impaired by eutrophication. The U.S. EPA Nutrient Criteria Technical Guidance Manual documents how reference reaches (i.e., reaches that are unimpacted or minimally impacted by humans) can be used to establish nutrient criteria. Reference status for nutrient and bioassessment sampling sites throughout the San Francisco Bay Region were determined according to the method described by Ode et al. (2015). Briefly, reference status was determined by land use and land-cover metrics that quantify natural characteristics and anthropogenic stressors at or upstream of sampling sites. For this study, sites excluded by the reference tool were added back to the reference pool if best professional judgement showed the tool misidentified a source of impact (e.g., flagged for agriculture when there is no agriculture in the watershed); the impacts were believed to be minimal (e.g., minimally used roads in a protected area); or it was part of a long-term reference study that was established before the reference screening tool was developed. Less than fifteen percent of reference sites (18 of 131 sites) were added back to the reference pool using best professional judgement.
Guideline Reference:	WQ data from the federal Water Quality Portal (WQP) assembled for the 2024 Integrated Report in Region 5.
Guideline Reference:	Nutrient Criteria Technical Guidance Manual Rivers and Streams. USEPA, Office of Water, Office of Science and Technology. Washington, D.C. EPA-822-B-00-002.
Spatial Representation:	The six sites samples on Arroyo Mocho were dispersed throughout the waterbody to represent the land use gradient (grazing/open space upstream and increasing urbanization downstream).
Temporal Representation:	Data were collected monthly from April-July 2019, which is representative of the algae growth period in the watershed. Arroyo Mocho typically dries after July and sampling is no longer possible.
Environmental Conditions:	Arroyo Mocho flows through the Livermore Valley and drains to Arroyo de la Laguna. Its major tributaries are Arroyo Las Positas and Tassajara Creek. The upper extent of Arroyo Mocho is non-perennial and includes cattle grazing and open space land uses. The downstream portion of Arroyo Mocho is a flood control channel which is fed primarily by Arroyo Las Positas during the dry season.
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (2017).
QAPP Information Reference(s):	Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	315684
Pollutant:	Phosphorus
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	9
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012, WY2013, WY2014, WY2015, WY2017, and WY2019 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 9 samples exceeded the evaluation guideline of 0.107 mg/L, which represents the 90th percentile of phosphorus concentrations at reference sites (i.e., minimally impacted sites) in San Francisco Bay Region.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
	Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Chapter 3.3.3 of the Water Quality Control Plan for the San Francisco Bay Basin states "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. Changes in chlorophyll a and associated phytoplankton communities follow complex dynamics that are sometimes associated with a discharge of biostimulatory substances. Irregular and extreme levels of chlorophyll a or phytoplankton blooms may indicate exceedance of this objective and require investigation."
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The 90th percentile of phosphorus concentrations in San Francisco Bay Region reference streams, 0.107 mg/L, was selected as the evaluation guideline, meaning ninety percent of reference sites will have concentrations at or below 0.107 mg/L for phosphorus. Currently, there are no numeric Water Quality Objectives or U.S. EPA criteria for algae-based indicators to determine if a water’s beneficial uses are impaired by eutrophication. The U.S. EPA Nutrient Criteria Technical Guidance Manual documents how reference reaches (i.e., reaches that are unimpacted or minimally impacted by humans) can be used to establish nutrient criteria. Reference status for nutrient and bioassessment sampling sites throughout the San Francisco Bay Region were determined according to the method described by Ode et al. (2015). Briefly, reference status was determined by land use and land-cover metrics that quantify natural characteristics and anthropogenic stressors at or upstream of sampling sites. For this study, sites excluded by the reference tool were added back to the reference pool if best professional judgement showed the tool misidentified a source of impact (e.g., flagged for agriculture when there is no agriculture in the watershed); the impacts were believed to be minimal (e.g., minimally used roads in a protected area); or it was part of a long-term reference study that was established before the reference screening tool was developed. Less than fifteen percent of reference sites (18 of 131 sites) were added back to the reference pool using best professional judgement.
Guideline Reference:	Nutrient Criteria Technical Guidance Manual Rivers and Streams. USEPA, Office of Water, Office of Science and Technology. Washington, D.C. EPA-822-B-00-002.
Guideline Reference:	WQ data from the federal Water Quality Portal (WQP) assembled for the 2024 Integrated Report in Region 5.
Spatial Representation:	Data were collected from 9 station(s). Station Code(s): 204R00100, 204R01471, 204R00473, 204R00292, 204R01023, 204R01828, 204R01497, 204R04251, and 204R01241
Temporal Representation:	Data for this waterbody were collected over the date range 2012-05-30 to 2019-06-17
Environmental Conditions:	Arroyo Mocho flows through the Livermore Valley and drains to Arroyo de la Laguna. Its major tributaries are Arroyo Las Positas and Tassajara Creek. The upper extent of Arroyo Mocho is non-perennial and includes cattle grazing and open space land uses. The downstream portion of Arroyo Mocho is a flood control channel which is fed primarily by Arroyo Las Positas during the dry season.
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	315690
Pollutant:	Nitrogen
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	17
Number of Exceedances:	4
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP Monitoring in WY2018 and WY2019 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 4 of the 17 samples exceeded the evaluation guideline of 0.736 mg/L, which represents the 90th percentile of total nitrogen concentrations at reference sites (i.e., minimally impacted sites) in San Francisco Bay Region.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Chapter 3.3.3 of the Water Quality Control Plan for the San Francisco Bay Basin states "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. Changes in chlorophyll a and associated phytoplankton communities follow complex dynamics that are sometimes associated with a discharge of biostimulatory substances. Irregular and extreme levels of chlorophyll a or phytoplankton blooms may indicate exceedance of this objective and require investigation."
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The 90th percentile of total nitrogen concentrations in San Francisco Bay Region reference streams, 0.736 mg/L, was selected as the evaluation guideline, meaning ninety percent of reference sites will have concentrations at or below 0.736 mg/L for total nitrogen. Currently, there are no numeric Water Quality Objectives or U.S. EPA criteria for algae-based indicators to determine if a water’s beneficial uses are impaired by eutrophication. The U.S. EPA Nutrient Criteria Technical Guidance Manual documents how reference reaches (i.e., reaches that are unimpacted or minimally impacted by humans) can be used to establish nutrient criteria. Reference status for nutrient and bioassessment sampling sites throughout the San Francisco Bay Region were determined according to the method described by Ode et al. (2015). Briefly, reference status was determined by land use and land-cover metrics that quantify natural characteristics and anthropogenic stressors at or upstream of sampling sites. For this study, sites excluded by the reference tool were added back to the reference pool if best professional judgement showed the tool misidentified a source of impact (e.g., flagged for agriculture when there is no agriculture in the watershed); the impacts were believed to be minimal (e.g., minimally used roads in a protected area); or it was part of a long-term reference study that was established before the reference screening tool was developed. Less than fifteen percent of reference sites (18 of 131 sites) were added back to the reference pool using best professional judgement.
Guideline Reference:	Endangered and Threatened Fishes in the Klamath River Basin Causes of Decline and Strategies for Recovery
Guideline Reference:	WQ data from the federal Water Quality Portal (WQP) assembled for the 2024 Integrated Report in Region 5.
Spatial Representation:	Data were collected from 6 station(s). Station Code(s): 204AMO030, 204AMO100, 204AMO130, 204AMO140, 204AMO165, 204AMO190.
Temporal Representation:	Data were collected in May 2018 and monthly from April-July 2019, which is representative of the algae growth period in the watershed. Arroyo Mocho typically dries after July and sampling is no longer possible.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (2017).
QAPP Information Reference(s):	Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	315689
Pollutant:	Nitrogen, Nitrate
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	9
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC WY2012, WY2013, WY2014, WY2015, WY2017 and WY2019 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of 9 samples exceeded the nitrate evaluation guideline of 1.0 mg/L.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Chapter 3.3.3 of the Water Quality Control Plan for the San Francisco Bay Basin states "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. Changes in chlorophyll a and associated phytoplankton communities follow complex dynamics that are sometimes associated with a discharge of biostimulatory substances. Irregular and extreme levels of chlorophyll a or phytoplankton blooms may indicate exceedance of this objective and require investigation."
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Worcester et al. (2010) used 1.0 mg/L NO3 to designate water bodies as impaired for aquatic life use if there was additional evidence of eutrophication (e.g., supersaturation of dissolved oxygen).
Guideline Reference:	Central Coast RegionTechnical Paper: Interpreting Narrative Objectives for Biostimulatory Substances for California Central Coast Waters. This method uses the Technical Approach for Developing California Nutrient Numeric Endpoints.
Spatial Representation:	Data were collected from 9 station(s). Station Code(s): 204R01023, 204R00292, 204R01828, 204R01241, 204R01497, 204R04251, 204R00100, 204R01471, and 204R00473.
Temporal Representation:	Data for this waterbody were collected over the date range 2012-05-30 to 2019-06-17.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	315688
Pollutant:	Nitrogen, Nitrate
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	17
Number of Exceedances:	2
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed nitrate data in WY2018 and WY2019 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 2 of 17 samples exceeded the nitrate evaluation guideline of 1.0 mg/L.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Chapter 3.3.3 of the Water Quality Control Plan for the San Francisco Bay Basin states "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. Changes in chlorophyll a and associated phytoplankton communities follow complex dynamics that are sometimes associated with a discharge of biostimulatory substances. Irregular and extreme levels of chlorophyll a or phytoplankton blooms may indicate exceedance of this objective and require investigation."
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	Worcester et al. (2010) used 1.0 mg/L NO3 as N to designate water bodies as impaired for aquatic life use if there was additional evidence of eutrophication (e.g., supersaturation of dissolved oxygen).
Guideline Reference:	Central Coast RegionTechnical Paper: Interpreting Narrative Objectives for Biostimulatory Substances for California Central Coast Waters. This method uses the Technical Approach for Developing California Nutrient Numeric Endpoints.
Spatial Representation:	Data were collected from 6 station(s). Station Code(s): 204AMO030, 204AMO100, 204AMO130, 204AMO140, 204AMO165, 204AMO180.
Temporal Representation:	Data were collected in May 2018 and monthly from April-July 2019, which is representative of the algae growth period in the watershed. Arroyo Mocho typically dries after July and sampling is no longer possible.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (2017).
QAPP Information Reference(s):	Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	282964
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Chlorophyll a.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2019-06-13
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	282896
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Chlorophyll a.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2019-06-13
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	282982
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorophyll a.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2018-05-14
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	283081
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorophyll a.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection).
Temporal Representation:	The samples were collected between the dates of 2019-05-07 and 2019-05-07
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	282868
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorophyll a.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence).
Temporal Representation:	The samples were collected between the dates of 2019-05-15 and 2019-05-15
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	282995
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Chlorophyll a.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2019-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	282856
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorophyll a.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road).
Temporal Representation:	The samples were collected between the dates of 2019-06-04 and 2019-06-04
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	283026
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorophyll a.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout).
Temporal Representation:	The samples were collected between the dates of 2019-05-09 and 2019-05-09
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	282914
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Chlorophyll a.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bot   DECISION ID 154212 Region 2      Arroyo Mocho   Pollutant: Benthic Community Effects Final Listing Decision: List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: New Decision Revision Status Revised Sources: A Source Unknown TMDL Priority: Low Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: For the 2024 Integrated Report, USEPA disapproved 44 benthic community effects decisions that were placed in Category 3. The data and information demonstrated that the biological community is degraded, and the waterbody is listed on the 303(d) list with at least one pollutant impairment affecting an aquatic life beneficial use. This was an interim approach used to provide time to develop the methodology to associate the pollutant as a potential cause of the degraded biology. The USEPA reviewed the appropriateness of these category placements and indicated that the most appropriate classification for these 44 waterbody-pollutant combinations is Category 5. This decision was updated to reflect direction from USEPA. Benthic Community Effects are being considered for placement on the CWA section 303(d) List under sections 3.9 of the Listing Policy. Under section 3.9, additional lines of evidence (LOEs) associating the Benthic Community Effects decision with a water or sediment concentration of pollutants other than benthic-macroinvertebrate bioassessment or habitat assessment LOEs are necessary to place a water body on the 303(d) List for Benthic Community Effects. Twenty-three line(s) of evidence evaluating benthic-macroinvertebrate bioassessment data is/are available in the administrative record to assess this indicator. Twenty-one of 23 benthic-macroinvertebrate samples exceed the California Stream Condition Index (CSCI) impairment threshold. Additionally, there are associated pollutant impairments on the waterbody (including but not necessarily limited to Toxicity, Temperature, and pH). Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for placing Benthic Community Effects in this waterbody segment on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 21 of 23 benthic-macroinvertebrate bioassessment samples had CSCI scores below 0.79. Therefore, this water body is exceeding the water quality threshold for the protection of the WARM and/or COLD beneficial use. 4. Pursuant to section 3.9 of the Listing Policy, the water segment has associated pollutant(s) samples that exceed water quality objectives. 5. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.   Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.   State Board Review of Regional Board Conclusion and Recommendation:   State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.   Listing Extent:     for steelhead was exceeded in 6 out of 12 deployments. High water temperatures exceeding 24 °C, that is a maximum short exposure temperature for survival of salmonids (EPA 1977) were also measured at three monitoring locations at lower and upper reaches of the Creek during spring and summer seasons. At the monitoring site in the lower reach of the Arroyo Mocho Creek high temperature persisted for up to 5.75 hours during spring while at the middle and upper reach it lasted from 5 to more than 9 hours.left" valign="top" width="33%">LOE Subgroup:Beneficial Use: ="top" width="33%">Objective/Criterion Reference: width="33%">Data and Information Type: Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 288451   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-02 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 4789   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat Aquatic Life Use: Wildlife Habitat   Number of Samples: 12 Number of Exceedances: 6   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Comprehensive water quality assessment was conducted at the Arroyo Mocho watershed as part of SWAMP assessment. Continuous field monitoring at 15 minute increments of temperature, dissolved oxygen, pH and specific conductance was conducted to determine temporal variability in basic water quality at five locations throughout the watershed. The measured temperatures ranged from 6.1°C to 27.72 °C and varied with season and location. The 17 °C criterion tom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 282961   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: Data Reference: Water Quality Monitoring and Bioassessment in Nine San Francisco Bay Region Watersheds: Walker Creek, Lagunitas Creek, San Leandro Creek, Wildcat Creek/San Pablo Creek, Suisun Creek, Arroyo Las Positas, Pescadero Creek/Butano Creek, San Gregorio Creek, and Stevens Creek/Permanente Creek. Oakland, CA: Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for enclosed bays and estuaries are specified in the "Water Quality Control Plan for Control of Temperature in the Coastal and Interstate Waters and Enclosed Bays of California" including any revisions to the plan. In addition, the following temperature objectives apply to surface waters: The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Sullivan et al. (2000) reviewed a wide range of studies incorporating information from laboratory-based research, field observations, and risk assessment approaches and developed criteria for assessing temperature risk to aquatic life. The 7-day mean temperature (maximum value of the 7-day moving average of the daily mean temperature) of 14.8°C was established as the upper threshold criterion for coho salmon and 17.0°C for steelhead trout. The risk assessment approach used by Sullivan et al. (2000) suggests that temperatures exceeding the above thresholds will cause 10% reduction in average fish growth compared to optimal conditions. Guideline Reference: An Analysis of the Effects of Temperature on Salmonids of the Pacific Northwest with Implications for Selecting Temperature Criteria   Spatial Representation: Temperature was measured at five sites located on the mainstem of Arroyo Mocho Creek. The highest temperatures were recorded at the monitoring location southeast of Livermore in August 2004. High temperatures also occurred in the lower reach of the Creek during the spring season of 2004. Temporal Representation: In 2004 and 2005 the SWAMP Program performed continuous monitoring of temperature at 15 minute intervals for periods of 1-2 weeks in each of three different seasons: winter (5 sites), spring (5 sites), and summer dry season (2 sites). Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 289059   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Dat QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 282912   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-05-07 and 2019-05-07 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 283010   Pollutant: Chlorophyll-a LOE Subgroup: Poa Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 288444   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 6 Number of Exceedances: 5   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 5 of 6 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-06-04 and 2019-06-04 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 282867   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall no//www.waterboards.ca.gov/water_issues/programs/tmdl/records/region_2/2010/ref3754.pdf" >Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 289107   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 12 Number of Exceedances: 3   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 3 of 12 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 282886   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-08-26 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 289003   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 4 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 4 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates oign="top" width="33%">Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 282557   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-05-15 and 2019-05-15 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 283009   Pollutant: Chlorophyll-a Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 268608   Pollutant: Toxicity LOE Subgroup: Toxicity Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 1   Data and Information Type: TOXICITY TESTING Data Used to Assess Water Quality: 1 of the 2 samples collected by BASMAA RMC Monitoring in WY2014 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Ceriodaphnia dubia for Survival, Selenastrum capricornutum for Total Cell Count, Pimephales promelas for Survival, Pimephales promelas for Biomass (wt/orig indiv), Ceriodaphnia dubia for Young/female, Hyalella azteca for Survival. The following tests exhibited toxicity: Selenastrum capricornutum for Total Cell Count on 2014-07-23. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated. Guideline Reference: Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013   Spatial Representation: The samples were collected at monitoring site: 204R00292 ( Arroyo Mocho just upstream of confluence with Arroyo de la Laguna ). Temporal Representation: The samples were collected between the dates of 2014-03-29 and 2014-07-23. Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 277498   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 28994   Pollutant: Toxicity LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 1   Data and Information Type: TOXICITY TESTING Data Used to Assess Water Quality: Three samples were collected in 2005 to evaluate water toxicity at two monitoring locations in Arroyo Mocho watershed. The toxicity tests included survival and reproduction of Ceriodaphnia, survival and growth of fathead minnow, and growth of Selenastrum. Ceriodaphnia growth was significantly lower than the control in one of three samples (dry season sample). Growth was 69.4 percent of the control for this sample. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Water toxicity was evaluated according to the SWAMP methodology. The U.S.EPA whole effluent toxicity protocol (U.S.EPA 1994) was used to test the effect of water samples on three freshwater test organisms. Statistical evaluation (alpha = 0.05) and a default threshold of 80% of the control value were used to establish whether water exhibited significant toxicity adversely impacting aquatic organisms. Guideline Reference: Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. EPA/600/4-91/002. Third Edition. July 1994 Guideline Reference: Revised approach to toxicity test acceptability criteria using a statistical performance assessment. Environmental Toxicology and Chemistry, vol. 16, No. 6, pp 1322¿1329   Spatial Representation: Data were collected at one sampling location, AMO070, located above Vulcan Bridge Zone 7, representing the Arroyo Mocho Creek. Temporal Representation: SWAMP samples were collected during wet (January), spring (April), and dry (June) seasons of 2005. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID:The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-04-24 and 2019-06-26 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 277910   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      268610   Pollutant: Toxicity LOE Subgroup: Toxicity Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 1   Data and Information Type: TOXICITY TESTING Data Used to Assess Water Quality: 1 of the 2 samples collected by BASMAA RMC Monitoring in WY2012 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Pimephales promelas for Biomass (wt/orig indiv), Selenastrum capricornutum for Total Cell Count, Ceriodaphnia dubia for Young/female, Ceriodaphnia dubia for Survival, Pimephales promelas for Survival, Hyalella azteca for Survival. The following tests exhibited toxicity: Pimephales promelas for Survival on 2012-03-14. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated. Guideline Reference: Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013   Spatial Representation: The samples were collected at monitoring site: 204R00100 ( Arroyo Mocho_BA_2012-204R00100 ). Temporal Representation: The samples were collected between the dates of 2012-03-14 and 2012-07-25. Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 283026   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Arroyo Mocho   LOE ID: 278422   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-03 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 277949   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 283081   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-05-07 and 2019-05-07 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 282995   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB> Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd). Temporal Representation: The samples were collected between the dates of 2019-04-30 and 2019-04-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278264   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd). Temporal Representation: The samples were collected between the dates of 2019-04-30 and 2019-04-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278418   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278357   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 282868   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-05-15 and 2019-05-15 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 286760   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 287331   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 7 Number of Exceedances: 5   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 5 of 7 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spr> Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-04-24 and 2019-06-26 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278731   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278082   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278256   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 4 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between thatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 306684   Pollutant: Benthic-Macroinvertebrate Bioassessments LOE Subgroup: Population/Community Degradation Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: Benthic macroinvertebrate surveys Data Used to Assess Water Quality: Water Board staff assessed data for 204AMO130 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.786844329 to 0.786844329. Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings   Spatial Representation: Samples were collected from station 204AMO130. Temporal Representation: Samples were collected from 5/9/2019 to 5/9/2019. Environmental Conditions: QAPP Information: Data were collected using Surface Water Ambient Monitoring Program protocols QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 306622   Pollutant: Benthic-Macroinvertebrate Bioassessments LOE Subgroup: Population/Community Degradation Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: Benthic macroinvertebrate surveys Data Used to Assess Water Quality: Water Board staff assessed data for 204AMO070 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.315975 to 0.315975. Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings   Spatial Representation: Samples were collected from station 204AMO070. Temporal Representation: Samples were collected from 4/12/2005 to 4/12/2005. Environmental Conditions: QAPP Information: Data were collected using Surface Water Ambient Monitoring Program protocols QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 306647   Pollutant: Benthic-Macroinvertebrate Bioassessments LOE Subgroup: Population/Community Degradation Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 2 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278106   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 277884   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 4   Data and Information Type: Benthic macroinvertebrate surveys Data Used to Assess Water Quality: Water Board staff assessed data for 204AMO140 to determine beneficial use support and the results are as follows: 2 of 2 samples exceeded the threshold. CSCI scores were from 0.558045193 to 0.628004285. Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings   Spatial Representation: Samples were collected from station 204AMO140. Temporal Representation: Samples were collected from 5/8/2018 to 5/8/2019. Environmental Conditions: QAPP Information: Data were collected using Surface Water Ambient Monitoring Program protocols QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 306671   Pollutant: Benthic-Macroinvertebrate Bioassessments LOE Subgroup: Population/Community Degradation Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: Benthic macroinvertebrate surveys Data Used to Assess Water Quality: Water Board staff assessed data for 204R01828 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.272188 to 0.272188. Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 277656   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-04-24 and 2019-05-30 Environmental Conditions: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings   Spatial Representation: Samples were collected from station 204R01828. Temporal Representation: Samples were collected from 5/20/2015 to 5/20/2015. Environmental Conditions: QAPP Information: Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 306623   Pollutant: Benthic-Macroinvertebrate Bioassessments LOE Subgroup: Population/Community Degradation Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: Benthic macroinvertebrate surveys Data Used to Assess Water Quality: Water Board staff assessed data for 204AMO100 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.670381 to 0.670381. Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings   QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278585   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-04-23 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 315687   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 202 Number of Exceedances: 83   Spatial Representation: Samples were collected from station 204AMO100. Temporal Representation: Samples were collected from 4/12/2005 to 4/12/2005. Environmental Conditions: QAPP Information: Data were collected using Surface Water Ambient Monitoring Program protocols QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 306683   Pollutant: Benthic-Macroinvertebrate Bioassessments LOE Subgroup: Population/Community Degradation Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: Benthic macroinvertebrate surveys Data Used to Assess Water Quality: Water Board staff assessed data for 204AMO165 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.747701078 to 0.747701078. Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings   Spatial Representation: Samples were collected from station 204AMO165. Temporal Representation: Samples were collected from 5/7/2019 to 5/7/2019. Environmental Conditions: QAPP Information: Data were collected using Surface Water Ambient Monitoring Program protocols QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 306658   Pollutant: Benthic-Macroinvertebrate Bioassessments LOE Subgroup: Population/Community Degradation Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: Benthic macroinvertebrate surveys Data Used to Assess Water Quality: Water Board staff assessed data for 204TASS01 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.280629323 to 0.280629323. Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings   Spatial Representation: Samples were collected from station 204TASS01. Temporal Representation: Samples were collected from 5/15/2019 to 5/15/2019. Environmental Conditions: QAPP Information: Data were collected using Surface Water Ambient Monitoring Program protocols QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 306636   Pollutant: Benthic-Macroinvertebrate Bioassessments LOE Subgroup: Population/Community Degradation Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed continuous dissolved oxygen data in WY2019 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 83 of 202 days (41%) exceeded the dissolved oxygen evaluation guideline of 13 mg/L, which represents supersaturated oxygen conditions and can be indicative of excessive algal growth. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Chapter 3.3.3 of the Water Quality Control Plan for the San Francisco Bay Basin states "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. Changes in chlorophyll a and associated phytoplankton communities follow complex dynamics that are sometimes associated with a discharge of biostimulatory substances. Irregular and extreme levels of chlorophyll a or phytoplankton blooms may indicate exceedance of this objective and require investigation." Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Worceter et al. (2010) recommends 13 mg/L dissolved oxygen as an appropriate upper value to screen both warm and cold water sites for oxygen supersaturation outside of reference ranges. Guideline Reference: Central Coast RegionTechnical Paper: Interpreting Narrative Objectives for Biostimulatory Substances for California Central Coast Waters. This method uses the Technical Approach for Developing California Nutrient Numeric Endpoints.   Spatial Representation: Data were collected from 3 station(s). Station Code(s): 204AMO100, 204AMO165, and 204AMO190 Temporal Representation: Dissolved oxygen data was recorded every 15 minutes using YSI sondes in the spring-summer of 2019. Sondes were deployed until the sites dried: 24 days at 204AMO100; 72 days at 204AMO165, and 106 days at 204AMO190. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (2017). QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 286861   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Benthic macroinvertebrate surveys Data Used to Assess Water Quality: Water Board staff assessed data for 204R00473 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.676338 to 0.676338. Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings   Spatial Representation: Samples were collected from station 204R00473. Temporal Representation: Samples were collected from 5/9/2013 to 5/9/2013. Environmental Conditions: QAPP Information: Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 306646   Pollutant: Benthic-Macroinvertebrate Bioassessments LOE Subgroup: Population/Community Degradation Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: Benthic macroinvertebrate surveys Data Used to Assess Water Quality: Water Board staff assessed data for 204R01471 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.224225 to 0.224225. Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings   Spatial Representation: Samples were collected from station 204R01471. Temporal Representation: Samples were collected from 5/22/2013 to 5/22/2013. Environmental Conditions: QAPP Information: Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 306612   Pollutant: Benthic-Macroinvertebrate Bioassessments LOE Subgroup: Population/Community Degradation Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: Benthic macroinvertebrate surveys Data Used to Assess Water Quality: Water Board staff assessed data for 204AMO200 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.585441 to 0.585441. Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings   Spatial Representation: Samples were collected from station 204AMO2 >Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 287205   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 12 Number of Exceedances: 2   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 2 of 12 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-08-26 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 286737   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 287006   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 287034   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-02 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 287331   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater 00. Temporal Representation: Samples were collected from 4/11/2005 to 4/11/2005. Environmental Conditions: QAPP Information: Data were collected using Surface Water Ambient Monitoring Program protocols QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 306611   Pollutant: Benthic-Macroinvertebrate Bioassessments LOE Subgroup: Population/Community Degradation Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 1   Data and Information Type: Benthic macroinvertebrate surveys Data Used to Assess Water Quality: Water Board staff assessed data for 204AMO180 to determine beneficial use support and the results are as follows: 1 of 3 samples exceeded the threshold. CSCI scores were from 0.673506667 to 0.937994. Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings   Spatial Representation: Samples were collected from station 204AMO180. Temporal Representation: Samples were collected from 4/11/2005 to 6/5/2019. Environmental Conditions: QAPP Information: Data were collected using Surface Water Ambient Monitoring Program protocols QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Number of Samples: 7 Number of Exceedances: 5   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 5 of 7 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 286910   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 6 Number of Exceedances: 4   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 4 of 6 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). TemporaRIGHT: 2%; PADDING-LEFT: 0%; FONT-WEIGHT: bold; PADDING-BOTTOM: 3px; WIDTH: 100%; text-align: left; PADDING-TOP: 3px; font-smooth: always">Arroyo Mocho   LOE ID: 306634   Pollutant: Benthic-Macroinvertebrate Bioassessments LOE Subgroup: Population/Community Degradation Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: Benthic macroinvertebrate surveys Data Used to Assess Water Quality: Water Board staff assessed data for 204PS0094 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.344929642 to 0.344929642. Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings   Spatial Representation: Samples were collected from station 204PS0094. Temporal Representation: Samples were collected from 7/14/2010 to 7/14/2010. Environmental Conditions: QAPP Information: Data were collected using Surface Water Ambient Monitoring Program protocols QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 306635   Pollutant: Benthic-Macroinvertebrate Bioassessments LOE Subgroup: Population/Community Degradation Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: Benthic macroinvertebrate surveys Data Used to Assess Water Quality: Water Board staff assessed data for 204R00100 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.339744 to 0.339744. Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings   Spatial Representation: Samples were collected from station 204R00100. Temporal Representation: Samples were collected from 5/30/2012 to 5/30/2012. Environmental Conditions: QAPP Information: Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 306682   Pollutant: Benthic-Macroinvertebrate Bioassessments LOE Subgroup: Population/Community Degradation Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 2   Data and Information Type: Benthic macroinvertebrate surveys Data Used to Assess Water Quality: Water Board staff assessed data for 204ALP020 to determine beneficial use support and the results are as follows: 2 of 2 samples exceeded the threshold. CSCI scores were from 0.604082263 to 0.661446763. Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 286745   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 4 Number of Exceedances: 3   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 3 of 4 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-05-30 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 287026   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings   Spatial Representation: Samples were collected from station 204ALP020. Temporal Representation: Samples were collected from 5/16/2018 to 6/13/2019. Environmental Conditions: QAPP Information: Data were collected using Surface Water Ambient Monitoring Program protocols QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 306648   Pollutant: Benthic-Macroinvertebrate Bioassessments LOE Subgroup: Population/Community Degradation Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: Benthic macroinvertebrate surveys Data Used to Assess Water Quality: Water Board staff assessed data for 204AMO195 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.645766977 to 0.645766977. Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings   Spatial Representation: Samples were collected from station 204AMO195. Temporal Representation: Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 277906   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-04-23 and 2019-07-23 Environmental Conditions: Samples were collected from 5/14/2018 to 5/14/2018. Environmental Conditions: QAPP Information: Data were collected using Surface Water Ambient Monitoring Program protocols QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 306659   Pollutant: Benthic-Macroinvertebrate Bioassessments LOE Subgroup: Population/Community Degradation Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: Benthic macroinvertebrate surveys Data Used to Assess Water Quality: Water Board staff assessed data for 204AMO190 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.595075868 to 0.595075868. Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings   Spatial Representation: Samples were collected from station 204AMO190. Temporal Representation: Samples were collected from 6/4/2019 to 6/4/2019. Environmental Conditions: QAPP Information: Data were collected using Surface Water Ambient Monitoring Program protocols QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 277925   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278443   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MO; PADDING-TOP: 3px; font-smooth: always">Arroyo Mocho   LOE ID: 306624   Pollutant: Benthic-Macroinvertebrate Bioassessments LOE Subgroup: Population/Community Degradation Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: Benthic macroinvertebrate surveys Data Used to Assess Water Quality: Water Board staff assessed data for 204AMO160 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.621941 to 0.621941. Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings   Spatial Representation: Samples were collected from station 204AMO160. Temporal Representation: Samples were collected from 4/12/2005 to 4/12/2005. Environmental Conditions: QAPP Information: Data were collected using Surface Water Ambient Monitoring Program protocols QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 306672   Pollutant: Benthic-Macroinvertebrate Bioassessments LOE Subgroup: Population/Community Degradation Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: Benthic macroinvertebrate surveys Data Used to Assess Water Quality: Water Board staff assessed data for 204R01497 to determineNITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 277841   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings   Spatial Representation: Samples were collected from station 204R01497. Temporal Representation: Samples were collected from 6/12/2017 to 6/12/2017. Environmental Conditions: QAPP Information: Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 306670   Pollutant: Benthic-Macroinvertebrate Bioassessments LOE Subgroup: Population/Community Degradation Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: Benthic macroinvertebrate surveys Data Used to Assess Water Quality: Water Board staff assessed data for 204R00292 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.233503 to 0.233503. Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The Callign="left" valign="top" width="67%">Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 277499   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-04-23 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 277901   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the watifornia Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.  Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings   Spatial Representation: Samples were collected from station 204R00292. Temporal Representation: Samples were collected from 5/7/2014 to 5/7/2014. Environmental Conditions: QAPP Information: Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154212, Benthic Community Effects Region 2      Arroyo Mocho   LOE ID: 288744   Pollutant: Temperature, water LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Not Recorded   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 7 Number of Exceedances: 5   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 5 of 7 samples exceeded the water quality threshold for Temperature. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Temperature objectives for surface waters are specified in the San Francisco Bay Regional Water Quality Control Plan. The following temperature objectives apply to surface waters: “- The natural receiving water temperature of inland surface waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses. - The temperature of any cold or warm freshwater habitat shall not be increased by more than 5°F (2.8°C) above natural receiving water temperature.” Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Per Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids (Carter 2008, Moyle 1976, and USEPA 1977), the lethal temperature evaluation guideline for both the steelhead adult migration and holding and the steelhead juvenile growth and rearing life stages is 24°C. Guideline Reference: Temperature criteria for freshwater fish: protocol and procedures. Ecological Research Series. EPA-600/3-77-061 (NTIS PB270032). Prepared by W.A. Brungs and B.R. Jones. U.S. Environmental Protection Agency, Washington, D.C Guideline Reference: Inland Fishes of California Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-08-27 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.     DECISION ID 154554 Region 2      Arroyo Mocho   Water align="left" valign="top" width="67%"> Pollutant: Eutrophication Final Listing Decision: List on 303(d) list (TMDL required list) Last Listing Cycle's Final Listing Decision: New Decision Revision Status Revised Sources: A Source Unknown TMDL Priority: Low Impairment from Pollutant or Pollution: Pollutant   Regional Board Conclusion: This pollutant is being considered for listing under sections 3.7.1 and 3.11 of the Listing Policy. Under section 3.7.1, an acceptable nutrient-related evaluation guideline is exceeded using the binomial distribution as described in section 3.1 for excessive algae growth, unnatural foam, odor, and taste. Waters may also be placed on the section 303(d) list when a significant nuisance condition exists as compared to reference conditions, or when nutrient concentrations cause or contribute to excessive algae growth. Under section 3.11, water segments shall be evaluated to determine whether the weight of evidence demonstrates that a water quality standard is not attained. When making a listing decision based on the situation-specific weight of evidence, the Regional Water Board must justify its recommendation by: 1. Providing any data or information including current conditions supporting the decision; 2. Describing in fact sheets how the data or information affords a substantial basis in fact from which the decision can be reasonably inferred; 3. Demonstrating that the weight of evidence of the data and information indicate that the water quality standard is not attained; and 4. Demonstrating that the approach used is scientifically defensible and reproducible. Eighty-three lines of evidence are available in the administrative record to assess these pollutants: (1) algae; (2) nitrogen; (3) nitrogen, nitrate; (4) total ammonia; (5) phosphorus; (6) chlorophyll-a (water column); (7) chlorophyll-a (benthic); (8) dissolved oxygen; and (9) pH. Based on the readily available data for this water body, the weight of evidence indicates that there is sufficient justification available in favor of adding this water segment-pollutant combination to the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used were collected by SWAMP and SWAMP-comparable programs which satisfy the data quality requirements of section 6.1.4 of the Policy. Sampling occurred at 20 sites between 2012-2019, so data are both spatially and temporally representative. Data were collected between April and August, so different stages of algal growth are represented in the dataset. 2. The evaluation of eutrophic conditions requires the weight of evidence approach because the evaluation process examining a stream’s trophic status requires measuring naturally occurring stream organisms (i.e., algae) and determining if the current amount of algae is affecting recreational beneficial uses or water quality parameters that influence aquatic life (e.g., pH and dissolved oxygen). Such an analysis requires the integration of secondary water quality indicators at sites with high algal biomass because the presence of algae alone does not demonstrate that aquatic impacts have occurred. For the lines of evidence regarding nutrients with direct toxic effects (e.g., un-ionized ammonia, total ammonia, and nitrate), Listing Policy Table 3.1 criteria for toxicants was used to determine if that aquatic life beneficial uses were affected by nutrient toxicity. 3. Nutrient-related evaluation guidelines for percent algae cover, total nitrogen, nitrate, and phosphorus were evaluated using the binomial distribution as described in section 3.1 of the Listing Policy. Five of 13 algae sampled exceeded the evaluation guideline of 30% cover and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. Four of 17 total nitrogen samples exceeded the evaluation guideline of 0.736 mg/L and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. Sixteen of 27 total phosphorus samples exceeded the evaluation guideline of 0.107 mg/L and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. The conventional parameters chlorophyll, dissolved oxygen, and pH were evaluated against binomial distribution tables as described in section 3.2 of the Listing Policy Four of 11 chlorophyll-a (water column) samples exceed the evaluation guideline of 40 ug/L and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. Six of 14 chlorophyll-a (benthic) samples exceed the evaluation guideline of 100 mg/m2 and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. Eighty-three of 202 days exceeded the dissolved oxygen evaluation guideline of 13 mg/L and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. Nineteen of 51 pH samples exceeded the evaluation guideline of 8.5 pH units and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. In addition to the aforementioned LOEs, continuous monitoring data showed daily dissolved oxygen swings greater than 5 mg/L for 106 of 202 days monitored, which is indicative of eutrophic conditions. There was generally strong agreement between indicators, meaning that sites exceeding evaluation guidelines for nutrients tended to show signs of nuisance algae growth or adverse effects to beneficial uses. 4. This process is scientifically defensible and reproducible. Data used to make this decision were collected using standardized SWAMP protocols and evaluated against U.S. EPA criteria, Basin Plan Water Quality Objectives, and technical report recommendations, when possible. When formal numeric objectives were not available, numeric evaluation guidelines were established using a reference-site approach (i.e., sites that are unimpacted or minimally impacted by humans) which was adapted from the U.S. EPA Nutrient Criteria Technical Guidance Manual. Reference status for nutrient and ber quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278516   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan     Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.   State Board Review of Regional Board Conclusion and Recommendation: The conventional parameters chlorophyll, dissolved oxygen, and pH were evaluated against binomial distribution tables as described in section 3.2 of the Listing Policy Four of 11 chlorophyll-a (water column) samples exceed the evaluation guideline of 40 ug/L and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. Six of 14 chlorophyll-a (benthic) samples exceed the evaluation guideline of 100 mg/m2 and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. Eighty-three of 202 days exceeded the dissolved oxygen evaluation guideline of 13 mg/L and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. Nineteen of 51 pH samples exceeded the evaluation guideline of 8.5 pH units and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. In addition to the aforementioned LOEs, continuous monitoring data showed daily dissolved oxygen swings greater than 5 mg/L for 106 of 202 days monitored, which is indicative of eutrophic conditions. There was generally strong agreement between indicators, meaning that sites exceeding evaluation guidelines for nutrients tended to show signs of nuisance algae growth or adverse effects to beneficial uses. 4. This process is scientifically defensible and reproducible. Data used to make this decision were collected using standardized SWAMP protocols and evaluated against U.S. EPA criteria, Basin Plan Water Quality Objectives, and technical report recommendations, when possible. When formal numeric objectives were not available, numeric evaluation guidelines were established using a reference-site approach (i.e., sites that are unimpacted or minimally impacted by humans) which was adapted from the U.S. EPA Nutrient Criteria Technical Guidance Manual. Reference status for nutrient and bioassessment sampling sites throughout the San Francisco Bay region were determined according to the method described by Ode et al. (2015).   State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.   Listing Extent:     Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 315692   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Not Recorded Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 9 Number of Exceedances: 5   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC WY2012, WY2013, WY2014, WY2015, WY2017 and WY2019 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 5 of 9 samples exceeded the benthic chlorophyll evaluation guideline of 100 mg/m2. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278752   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278061   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Chapter 3.3.3 of the Water Quality Control Plan for the San Francisco Bay Basin states "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. Changes in chlorophyll a and associated phytoplankton communities follow complex dynamics that are sometimes associated with a discharge of biostimulatory substances. Irregular and extreme levels of chlorophyll a or phytoplankton blooms may indicate exceedance of this objective and require investigation." Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Creager et al. (2006) recommends an evaluation guideline of 100 mg/m2 for benthic chlorophyll-a. This guideline represents the Beneficial Use Risk Classification I/II (BURC I/II) boundary, which is a threshold below which nutrients do not present a significant risk of impairment as described in the Technical Approach to Develop Nutrient Numeric Endpoints for California. Guideline Reference: Technical Approach to Develop Nutrient Numeric Endpoints for California. U.S. EPA Region IX. State Water Resources Control Board. 68-C-02-108-To-111   Spatial Representation: Data were collected from 9 station(s). Station Code(s): 204R01023, 204R00292, 204R01828, 204R01241, 204R01497, 204R04251, 204R00100, 204R01471, and 204R00473. Temporal Representation: Data for this waterbody were collected over the date range 2012-05-30 to 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 315693   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Not Recorded Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 5 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP Monitoring in WY2018 and WY2019 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 1 of 5 samples exceeded the benthic chlorophyll evaluation guideline of 100 mg/m2. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Chapter 3.3.3 of the Water Quality Control Plan for the San Francisco Bay Basin states "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. Changes in chlorophyll a and associated phytoplankton communities follow complex dynamics that are sometimes associated with a discharge of biostimulatory substances. Irregular and extreme levels of chlorophyll a or phytoplankton blooms may indicate exceedance of this objective and require investigation." Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Creager et al. (2006) recommends an evaluation guideline of 100 mg/m2 for benthic chlorophyll-a. This guideline represents the Beneficial Use Risk Classification I/II (BURC I/II) boundary, which is a threshold below which nutrients do not present a significant risk of impairment as described in the Technical Approach to Develop Nutrient Numeric Endpoints for California. Guideline Reference: SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-24 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278286   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-04-24 and 2019-05-30 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278401   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 277903   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Technical Approach to Develop Nutrient Numeric Endpoints for California. U.S. EPA Region IX. State Water Resources Control Board. 68-C-02-108-To-111   Spatial Representation: Data were collected from 3 station(s). Station Code(s): 204AMO140, 204AMO180, and 204AMO190 Temporal Representation: Data for this waterbody were collected over the date range 2018-05-08 to 2019-06-05 Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (2017). QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 286758   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd). Temporal Representation: The samples were collected between the dates of 2019-04-30 and 2019-04-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 286746   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278753   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 5 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-07-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 286901   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Region 2      Arroyo Mocho   LOE ID: 278459   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-04-23 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278081   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration ("33%">Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 286988   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 315686   Pollutant: Algae LOE Subgroup: Pollutant-Nuisance Matrix: Water Fraction: Percent   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 13 Number of Exceedances: 5   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: To estimate percent algae cover, SWAMP staff established a 50 m section that is representative of the stream reach. The 50 m section was divided into 5 m longitudinal transects and visually estimated the percent cover of filamentous green algae in 10% bins. The average of the ten transects was calculated to get an overall percent cover for each site. Sites were visited monthly to calculate changes across the dry season. To ensure consistency, the same field crew member conducted the estimates for the entire project. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Chapter 3.3.3 of the Water Quality Control Plan for the San Francisco Bay Basin states "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. Changes in chlorophyll a and associated phytoplankton communities follow complex dynamics that are sometimes associated with a discharge of biostimulatory substances. Irregular and extreme levels of chlorophyll a or phytoplankton blooms may indicate exceedance of this objective and require investigation." Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Biggs (2000) recommends a 30 percent cover by filamentous green or brown algae as a threshold associated with benthic chlorophyll-a levels consistent with protection of recreation and fisheries Guideline Reference: New Zealand Periphyton Guideline: Detecting Monitoring and Managing Enrichment of Streams   Spatial Representation: Data were collected from 6 station(s). Station Code(s): 204AMO030, 204AMO100, 204AMO165, 204AMO190. Temporal Representation: Data were collected monthly from April-August 2019, which is representative of the algae growth period in the watershed. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (2017). QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 315683   Pollutant: Phosphorus LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 18 Number of Exceedances: 16   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Sixteen of 18 samples had total phosphorus concentrations above 0.107 mg/L, which represents the 90th percentile of phosphorus concentrations at reference sites (i.e., minimally impacted sites) in San Francisco Bay Region. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Chapter 3.3.3 of the Water Quality Control Plan for the San Francisco Bay Basin states "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. Changes in chlorophyll a and associated phytoplankton communities follow complex dynamics that are sometimes associated with a discharge of biostimulatory substances. Irregular and extreme levels of chlorophyll a or phytoplankton blooms may indicate exceedance of this objective and require investigation." Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The 90th percentile of phosphorus concentrations in San Francisco Bay Region reference streams, 0.107 mg/L, was selected as the evaluation guideline, meaning ninety percent of reference sites will have concentrations at or below 0.107 mg/L for phosphorus. Currently, there are no numeric Water Quality Objectives or U.S. EPA criteria for algae-based indicators to determine if a water’s beneficial uses are impaired by eutrophication. The U.S. EPA Nutrient Criteria Technical Guidance Manual documents how reference reaches (i.e., reaches that are unimpacted or minimally impacted by humans) can be used to establish nutrient criteria. Reference status for nutrient and bioassessment sampling sites throughout the San Francisco Bay Region were determined according to the method described by Ode et al. (2015). Briefly, reference status was determined by land use and land-cover metrics that quantify natural characteristics and anthropogenic stressors at or upstream of sampling sites. For this study, sites excluded by the reference tool were added back to the reference pool if best professional judgement showed the tool misidentified a source of impact (e.g., flagged for agriculture when there is no agriculture in the watershed); the impacts were believed to be minimal (e.g., minimally used roads in a protected area); or it was part of a long-term reference study that was established before the reference screening tool was developed. Less than fifteen percent of reference sites (18 of 131 sites) were added back to the reference pool using best professional judgement. Guideline Reference: WQ data from the federal Water Quality Portal (WQP) assembled for the 2024 Integrated Report in Region 5. Guideline Reference: Nutrient Criteria Technical Guidance Manual Rivers and Streams. USEPA, Office of Water, Office of Science and Technology. Washington, D.C. EPA-822-B-00-002.   Spatial Representation: The six sites samples on Arroyo Mocho were dispersed throughout the waterbody to represent the land use gradient (grazing/open space upstream and increasing urbanization downstream). Temporal Representation: Data were collected monthly from April-July 2019, which is representative of the algae growth period in the watershed. Arroyo Mocho typically dries after July and sampling is no longer possible. Environmental Conditions: Arroyo Mocho flows through the Livermore Valley and drains to Arroyo de la Laguna. Its major tributaries are Arroyo Las Positas and Tassajara Creek. The upper extent of Arroyo Mocho is non-perennial and includes cattle grazing and open space land uses. The downstream portion of Arroyo Mocho is a flood control channel which is fed primarily by Arroyo Las Positas during the dry season. QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (2017). QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 315684   Pollutant: Phosphorus LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 9 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012, WY2013, WY2014, WY2015, WY2017, and WY2019 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of the 9 samples exceeded the evaluation guideline of 0.107 mg/L, which represents the 90th percentile of phosphorus concentrations at reference sites (i.e., minimally impacted sites) in San Francisco Bay Region. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Chapter 3.3.3 of the Water Quality Control Plan for the San Francisco Bay Basin states "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. Changes in chlorophyll a and associated phytoplankton communities follow complex dynamics that are sometimes associated with a discharge of biostimulatory substances. Irregular and extreme levels of chlorophyll a or phytoplankton blooms may indicate exceedance of this objective and require investigation." Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The 90th percentile of phosphorus concentrations in San Francisco Bay Region reference streams, 0.107 mg/L, was selected as the evaluation guideline, meaning ninety percent of reference sites will have concentrations at or below 0.107 mg/L for phosphorus. Currently, there are no numeric Water Quality Objectives or U.S. EPA criteria for algae-based indicators to determine if a water’s beneficial uses are impaired by eutrophication. The U.S. EPA Nutrient Criteria Technical Guidance Manual documents how reference reaches (i.e., reaches that are unimpacted or minimally impacted by humans) can be used to establish nutrient criteria. Reference status for nutrient and bioassessment sampling sites throughout the San Francisco Bay Region were determined according to the method described by Ode et al. (2015). Briefly, reference status was determined by land use and land-cover metrics that quantify natural characteristics and anthropogenic stressors at or upstream of sampling sites. For this study, sites excluded by the reference tool were added back to the reference pool if best professional judgement showed the tool misidentified a source of impact (e.g., flagged for agriculture when there is no agriculture in the watershed); the impacts were believed to be minimal (e.g., minimally used roads in a protected area); or it was part of a long-term reference study that was established before the reference screening tool was developed. Less than fifteen percent of reference sites (18 of 131 sites) were added back to the reference pool using best professional judgement. Guideline Reference: Nutrient Criteria Technical Guidance Manual Rivers and Streams. USEPA, Office of Water, Office of Science and Technology. Washington, D.C. EPA-822-B-00-002. Guideline Reference: WQ data from the federal Water Quality Portal (WQP) assembled for the 2024 Integrated Report in Region 5.   Spatial Representation: Data were collected from 9 station(s). Station Code(s): 204R00100, 204R01471, 204R00473, 204R00292, 204R01023, 204R01828, 204R01497, 204R04251, and 204R01241 Temporal Representation: Data for this waterbody were collected over the date range 2012-05-30 to 2019-06-17 Environmental Conditions: Arroyo Mocho flows through the Livermore Valley and drains to Arroyo de la Laguna. Its major tributaries are Arroyo Las Positas and Tassajara Creek. The upper extent of Arroyo Mocho is non-perennial and includes cattle grazing and open space land uses. The downstream portion of Arroyo Mocho is a flood control channel which is fed primarily by Arroyo Las Positas during the dry season. QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 315690   Pollutant: Nitrogen LOE Subgroup: Polluexpressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-03 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278489   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 17 Number of Exceedances: 4   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP Monitoring in WY2018 and WY2019 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 4 of the 17 samples exceeded the evaluation guideline of 0.736 mg/L, which represents the 90th percentile of total nitrogen concentrations at reference sites (i.e., minimally impacted sites) in San Francisco Bay Region. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Chapter 3.3.3 of the Water Quality Control Plan for the San Francisco Bay Basin states "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. Changes in chlorophyll a and associated phytoplankton communities follow complex dynamics that are sometimes associated with a discharge of biostimulatory substances. Irregular and extreme levels of chlorophyll a or phytoplankton blooms may indicate exceedance of this objective and require investigation." Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: The 90th percentile of total nitrogen concentrations in San Francisco Bay Region reference streams, 0.736 mg/L, was selected as the evaluation guideline, meaning ninety percent of reference sites will have concentrations at or below 0.736 mg/L for total nitrogen. Currently, there are no numeric Water Quality Objectives or U.S. EPA criteria for algae-based indicators to determine if a water’s beneficial uses are impaired by eutrophication. The U.S. EPA Nutrient Criteria Technical Guidance Manual documents how reference reaches (i.e., reaches that are unimpacted or minimally impacted by humans) can be used to establish nutrient criteria. Reference status for nutrient and bioassessment sampling sites throughout the San Francisco Bay Region were determined according to the method described by Ode et al. (2015). Briefly, reference status was determined by land use and land-cover metrics that quantify natural characteristics and anthropogenic stressors at or upstream of sampling sites. For this study, sites excluded by the reference tool were added back to the reference pool if best professional judgement showed the tool misidentified a source of impact (e.g., flagged for agriculture when there is no agriculture in the watershed); the impacts were believed to be minimal (e.g., minimally used roads in a protected area); or it was part of a long-term reference study that was established before the reference screening tool was developed. Less than fifteen percent of reference sites (18 of 131 sites) were added back to the reference pool using best professional judgement. Guideline Reference: Endangered and Threatened Fishes in the Klamath River Basin Causes of Decline and Strategies for Recovery Guideline Reference: WQ data from the federal Water Quality Portal (WQP) assembled for the 2024 Integrated Report in Region 5.   Spatial Representation: Data were collected from 6 station(s). Station Code(s): 204AMO030, 204AMO100, 204AMO130, 204AMO140, 204AMO165, 204AMO190. Temporal Representation: Data were collected in May 2018 and monthly from April-July 2019, which is representative of the algae growth period in the watershed. Arroyo Mocho typically dries after July and sampling is no longer possible. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (2017). QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 315689   Pollutant: Nitrogen, Nitrate LOE Subgroup: Pollutant-Water Arroyo Mocho   LOE ID: 278808   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278817   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterip" width="33%">Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 9 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC WY2012, WY2013, WY2014, WY2015, WY2017 and WY2019 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 0 of 9 samples exceeded the nitrate evaluation guideline of 1.0 mg/L. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Chapter 3.3.3 of the Water Quality Control Plan for the San Francisco Bay Basin states "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. Changes in chlorophyll a and associated phytoplankton communities follow complex dynamics that are sometimes associated with a discharge of biostimulatory substances. Irregular and extreme levels of chlorophyll a or phytoplankton blooms may indicate exceedance of this objective and require investigation." Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Worcester et al. (2010) used 1.0 mg/L NO3 to designate water bodies as impaired for aquatic life use if there was additional evidence of eutrophication (e.g., supersaturation of dissolved oxygen). Guideline Reference: Central Coast RegionTechnical Paper: Interpreting Narrative Objectives for Biostimulatory Substances for California Central Coast Waters. This method uses the Technical Approach for Developing California Nutrient Numeric Endpoints.   Spatial Representation: Data were collected from 9 station(s). Station Code(s): 204R01023, 204R00292, 204R01828, 204R01241, 204R01497, 204R04251, 204R00100, 204R01471, and 204R00473. Temporal Representation: Data for this waterbody were collected over the date range 2012-05-30 to 2019-06-17. Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 315688   Pollutant: Nitrogen, Nitrate LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 17 Number of Exceedances: 2   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed nitrate data in WY2018 and WY2019 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 2 of 17 samples exceeded the nitrate evaluation guideline of 1.0 mg/L. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Chapter 3.3.3 of the Water Quality Control Plan for the San Francisco Bay Basin states "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. Changes in chlorophyll a and associated phytoplankton communities follow complex dynamics that are sometimes associated with a discharge of biostimulatory substances. Irregular and extreme levels of chlorophyll a or phytoplankton blooms may indicate exceedance of this objective and require investigation." Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Worcester et al. (2010) used 1.0 mg/L NO3 as N to designate water bodies as impaired for aquatic life use if there was additional evidence of eutrophication (e.g., supersaturation of dissolved oxygen). Guideline Reference: Central Coast RegionTechnical Paper: Interpreting Narrative Objectives for Biostimulatory Substances for California Central Coast Waters. This method uses the Technical Approach for Developing California Nutrient Numeric Endpoints.   Spatial Representation: Data were collected from 6 station(s). Station Code(s): 204AMO030, 204AMO100, 204AMO130, 204AMO140, 204AMO165, 204AMO180. Temporal Representation: Data were collected in May 2018 and monthly from April-July 2019, which is representative of the algae growth period in the watershed. Arroyo Mocho typically dries after July and sampling is no longer possible. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (2017). QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 282964   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 277682   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-24 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278773   Pollutant: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-06-13 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 282896   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-06-13 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements >Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278358   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 282982   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 283081   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Tspan="2">Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278754   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278750   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total otal   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-05-07 and 2019-05-07 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 282868   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278421   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were colalign="left" valign="top" width="33%">Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence). Temporal Representation: The samples were collected between the dates of 2019-05-15 and 2019-05-15 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 282995   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 286760   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 286989   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 282856   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-06-04 and 2019-06-04 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 283026   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 286742   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 282914   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 282961   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 286741   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-03 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 287068   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 286887   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 282912   Pollutant: Chlorophyll-a LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorophyll a. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L. Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-05-07 and 2019-05-07 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 283010   Pollutant: Chlorophyll-a LOE Subgroup: Pon="top" width="67%">SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 28967   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 12 Number of Exceedances: 4   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Comprehensive water quality assessment was conducted at Arroyo Mocho Creek watershed as part of SWAMP assessment in 2004 and 2005. Continuous field monitoring of temperature, dissolved oxygen, pH, and specific conductance to determine temporal variability in basic water quality at one or two locations. The pH ranged from 7.0 to 9.2 and varied with season. The pH exceeded the maximum of 8.5 four times (9.2, 9.1, 8.8, 8.6) in all three (spring, summer, winter) seasons. The pH did not go below the minimum during any sampling event. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: pH was measured at two sites in summer 2004 and at five sites in spring 2004 and winter 2005 located within the Arroyo Mocho watershed that are representative of the entire watershed. Temporal Representation: At all locations the SWAMP performed continuous monitoring of pH at 15 minute intervals lasting 7-13 days during spring (April 2004), summer dry season (August 2004), and winter wet season (February 2005). Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)   llutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorophyll a.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road).
Temporal Representation:	The samples were collected between the dates of 2019-06-04 and 2019-06-04
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	282867
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorophyll a.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout).
Temporal Representation:	The samples were collected between the dates of 2019-05-09 and 2019-05-09
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	282886
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Chlorophyll a.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2019-06-05
DECISION ID	141767	Region 2
Arroyo Mocho

Pollutant:	Toxicity
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for listing under section 3.6 of the Listing Policy. Under section 3.6 a single line of evidence is necessary to assess listing status. Ten lines of evidence are available in the administrative record to assess this pollutant. This water body experiences toxicity. Based on the readily available data for this water body, the weight of evidence indicates that there is sufficient justification available in favor of adding this water segment-pollutant combination to the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data concerning current conditions and supporting the listing decision satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. Three out of seven water samples exhibited water toxicity. The number of samples with detected water toxicity exceeds the allowable frequency listed in Table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

LOE Subgroup: >

Line of Evidence (LOE) for Decision ID 141767, Toxicity Region 2      Arroyo Mocho
LOE ID:	268690
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	0 of the 1 samples collected by BASMAA RMC Monitoring in WY2012 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Survival, Hyalella azteca for Growth (wt/surv indiv).
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00100 ( Arroyo Mocho_BA_2012-204R00100 ).
Temporal Representation:	The samples were collected between the dates of 2012-07-25 and 2012-07-25.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141767, Toxicity Region 2      Arroyo Mocho
LOE ID:	268608
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	1 of the 2 samples collected by BASMAA RMC Monitoring in WY2014 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Ceriodaphnia dubia for Survival, Selenastrum capricornutum for Total Cell Count, Pimephales promelas for Survival, Pimephales promelas for Biomass (wt/orig indiv), Ceriodaphnia dubia for Young/female, Hyalella azteca for Survival. The following tests exhibited toxicity: Selenastrum capricornutum for Total Cell Count on 2014-07-23.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00292 ( Arroyo Mocho just upstream of confluence with Arroyo de la Laguna ).
Temporal Representation:	The samples were collected between the dates of 2014-03-29 and 2014-07-23.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141767, Toxicity Region 2      Arroyo Mocho
LOE ID:	268682
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	0 of the 1 samples collected by BASMAA RMC Monitoring in WY2012 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Survival, Hyalella azteca for Growth (wt/surv indiv).
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	282557
Pollutant:	Chlorophyll-a
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chlorophyll a.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence).
Temporal Representation:	The samples were collected between the dates of 2019-05-15 and 2019-05-15
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	283009
Pollutant:	Chlorophyll-a
Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00100 ( Arroyo Mocho_BA_2012-204R00100 ).
Temporal Representation:	The samples were collected between the dates of 2012-07-25 and 2012-07-25.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141767, Toxicity Region 2      Arroyo Mocho
LOE ID:	268662
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	0 of the 1 samples collected by BASMAA RMC Monitoring in WY2014 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Growth (wt/surv indiv), Hyalella azteca for Survival.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Chlorophyll a.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	North Carolina Administrative code (NCAC), Title 15A – Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference:	North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2019-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	277498
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00292 ( Arroyo Mocho just upstream of confluence with Arroyo de la Laguna ).
Temporal Representation:	The samples were collected between the dates of 2014-07-23 and 2014-07-23.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141767, Toxicity Region 2      Arroyo Mocho
LOE ID:	268610
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	1 of the 2 samples collected by BASMAA RMC Monitoring in WY2012 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Pimephales promelas for Biomass (wt/orig indiv), Selenastrum capricornutum for Total Cell Count, Ceriodaphnia dubia for Young/female, Ceriodaphnia dubia for Survival, Pimephales promelas for Survival, Hyalella azteca for Survival. The following tests exhibited toxicity: Pimephales promelas for Survival on 2012-03-14.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collectedalign="top" width="67%">The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road).
Temporal Representation:	The samples were collected between the dates of 2019-04-24 and 2019-06-26
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	277910
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471).
Temporal Representation:	The samples were collected between the dates of 2013-05-22 and 2013-05-22
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	278422
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-04-03
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	277949
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Temporal Representation:	The samples were collected between the dates of 2012-03-14 and 2012-07-25.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141767, Toxicity Region 2      Arroyo Mocho
LOE ID:	268670
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	1 of the 2 samples collected by BASMAA RMC Monitoring in WY2014 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Ceriodaphnia dubia for Survival, Selenastrum capricornutum for Total Cell Count, Pimephales promelas for Survival, Pimephales promelas for Biomass (wt/orig indiv), Ceriodaphnia dubia for Young/female, Hyalella azteca for Survival. The following tests exhibited toxicity: Selenastrum capricornutum for Total Cell Count on 2014-07-23.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00292 ( Arroyo Mocho just upstream of confluence with Arroyo de la Laguna ).
Temporal Representation:	The samples were collected between the dates of 2014-03-29 and 2014-07-23.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.	Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd).
Temporal Representation:	The samples were collected between the dates of 2019-04-30 and 2019-04-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	278264
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd).
Temporal Representation:	The samples were collected between the dates of 2019-04-30 and 2019-04-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	278418
Pollutant:	Nitrogen, ammonia (Total Ammonia)
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141767, Toxicity Region 2      Arroyo Mocho
LOE ID:	268621
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	0 of the 1 samples collected by BASMAA RMC Monitoring in WY2014 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Growth (wt/surv indiv), Hyalella azteca for Survival.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00292 ( Arroyo Mocho just upstream of confluence with Arroyo de la Laguna ).
Temporal Representation:	The samples were collected between the dates of 2014-07-23 and 2014-07-23.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Region 2      Line of Evidence (LOE) for Decision ID 141767, Toxicity LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278357   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Arroyo Mocho
LOE ID:	28994
Pollutant:	Toxicity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	1
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	Three samples were collected in 2005 to evaluate water toxicity at two monitoring locations in Arroyo Mocho watershed. The toxicity tests included survival and reproduction of Ceriodaphnia, survival and growth of fathead minnow, and growth of Selenastrum. Ceriodaphnia growth was significantly lower than the control in one of three samples (dry season sample). Growth was 69.4 percent of the control for this sample.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Water toxicity was evaluated according to the SWAMP methodology. The U.S.EPA whole effluent toxicity protocol (U.S.EPA 1994) was used to test the effect of water samples on three freshwater test organisms. Statistical evaluation (alpha = 0.05) and a default threshold of 80% of the control value were used to establish whether water exhibited significant toxicity adversely impacting aquatic organisms.
Guideline Reference:	Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. EPA/600/4-91/002. Third Edition. July 1994
Guideline Reference:	Revised approach to toxicity test acceptability criteria using a statistical performance assessment. Environmental Toxicology and Chemistry, vol. 16, No. 6, pp 1322¿1329
Spatial Representation:	Data were collected at one sampling location, AMO070, located above Vulcan Bridge Zone 7, representing the Arroyo Mocho Creek.
Temporal Representation:	SWAMP samples were collected during wet (January), spring (April), and dry (June) seasons of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141767, Toxicity Region 2      Arroyo Mocho
LOE ID:	28832
Pollutant:	Sediment Toxicity
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Toxicity testing of sediments
Data Used to Assess Water Quality:	Data used to evaluate sediment toxicity comprise one sediment sample collected by the SWAMP in 2005. No toxicity or adverse affects were exhibited for Hyallela azteca.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment toxicity was evaluated according to the SWAMP methodology. Sample toxicity was determined by comparing mean organism response in samples and in negative controls. Statistical evaluation (alpha = 0.05) and a default threshold of 80% of the control value were used to establish whether the sediment exhibited significant toxicity adversely impacting aquatic organisms.
Guideline Reference:	Revised approach to toxicity test acceptability criteria using a statistical performance assessment. Environmental Toxicology and Chemistry, vol. 16, No. 6, pp 1322¿1329
Spatial Representation:	One sediment sample was collected at a "watershed integrator" site located close to the mouth of Arroyo Mocho watershed (above Vulcan Bridge at zone 7).
Temporal Representation:	Sample was collected in April of 2005.
Environmental Conditions:
QAPP Information:	Samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141767, Toxicity Region 2      Arroyo Mocho
LOE ID:	268650
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	1 of the 2 samples collected by BASMAA RMC Monitoring in WY2012 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Pimephales promelas for Biomass (wt/orig indiv), Selenastrum capricornutum for Total Cell Count, Ceriodaphnia dubia for Young/female, Ceriodaphnia dubia for Survival, Pimephales promelas for Survival, Hyalella azteca for Survival. The following tests exhibited toxicity: Pimephales promelas for Survival on 2012-03-14.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00100 ( Arroyo Mocho_BA_2012-204R00100 ).
Temporal Representation:	The samples were collected between the dates of 2012-03-14 and 2012-07-25.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

r> Spatial Representation: The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road). Temporal Representation: The samples were collected between the dates of 2019-04-24 and 2019-06-26 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 278731   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 278082   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100). Temporal Representation: The samples were collected between the dates of 2012-05-30 and 2012-05-30 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 278256   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 4 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between th

DECISION ID	141759	Region 2
Arroyo Mocho

Pollutant:	pH
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence are available in the administrative record to assess this pollutant. Twenty-three of the sixty-three samples exceed the Basin Plan objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Twenty-three of the sixty-three samples exceed the Basin Plan objective and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:	Elevated pH in Arroyo Mocho is likely due to nuisance algae growth. See listing decision for eutrophication (decision ID 154554).

n="2"> Number of Samples:

Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	287068
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	278106
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2018-05-14
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	277884
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	4
Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd).
Temporal Representation:	The samples were collected between the dates of 2017-06-12 and 2017-06-12
Environmental Conditions:
QAPP Information:	EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s):	BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286901
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd).
Temporal Representation:	The samples were collected between the dates of 2019-06-17 and 2019-06-17
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro). Temporal Representation: The samples were collected between the dates of 2018-05-16 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 277656   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-04-24 and 2019-05-30 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 278585   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-04-23 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 315687   Pollutant: Oxygen, Dissolved LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 202 Number of Exceedances: 83   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed continuous dissolved oxygen data in WY2019 data for Arroyo Mocho to determine beneficial use support and the results are as follows: 83 of 202 days (41%) exceeded the dissolved oxygen evaluation guideline of 13 mg/L, which represents supersaturated oxygen conditions and can be indicative of excessive algal growth. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Chapter 3.3.3 of the Water Quality Control Plan for the San Francisco Bay Basin states "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. Changes in chlorophyll a and associated phytoplankton communities follow complex dynamics that are sometimes associated with a discharge of biostimulatory substances. Irregular and extreme levels of chlorophyll a or phytoplankton blooms may indicate exceedance of this objective and require investigation." Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Worceter et al. (2010) recommends 13 mg/L dissolved oxygen as an appropriate upper value to screen both warm and cold water sites for oxygen supersaturation outside of reference ranges. Guideline Reference: Central Coast RegionTechnical Paper: Interpreting Narrative Objectives for Biostimulatory Substances for California Central Coast Waters. This method uses the Technical Approach for Developing California Nutrient Numeric Endpoints.   Spatial Representation: Data were collected from 3 station(s). Station Code(s): 204AMO100, 204AMO165, and 204AMO190 Temporal Representation: Dissolved oxygen data was recorded every 15 minutes using YSI sondes in the spring-summer of 2019. Sondes were deployed until the sites dried: 24 days at 204AMO100; 72 days at 204AMO165, and 106 days at 204AMO190. Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (2017). QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program   Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho   LOE ID: 286861   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Arroyo Mocho
LOE ID:	287205
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	12
Number of Exceedances:	2
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 2 of 12 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2019-08-26
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	287034
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)).
Temporal Representation:	The samples were collected between the dates of 2019-04-02 and 2019-04-24
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286989
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2019-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471).
Temporal Representation:	The samples were collected between the dates of 2013-05-22 and 2013-05-22
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	287205
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	12
Number of Exceedances:	2
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 2 of 12 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2019-08-26
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	286737
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
LOE ID:	287331
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	5
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 5 of 7 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-08-27
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286737
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	The samples were collected between the dates of 2014-05-07 and 2014-05-07
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	287006
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	The samples were collected between the dates of 2014-05-07 and 2014-05-07
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286742
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout).
Temporal Representation:	The samples were collected between the dates of 2019-05-09 and 2019-05-09
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286746
Pollutant:	Spatial Representation:	The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.).
Temporal Representation:	The samples were collected between the dates of 2015-05-20 and 2015-05-20
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	287034
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)).
Temporal Representation:	The samples were collected between the dates of 2019-04-02 and 2019-04-24
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	287331
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater lign="top" width="67%">pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-07-24
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286741
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Number of Samples:	7
Number of Exceedances:	5
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 5 of 7 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-08-27
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	286910
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	6
Number of Exceedances:	4
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 4 of 6 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence).
Temporaft" valign="top" width="33%">Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-04-03
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286760
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2019-06-05
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286887
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	The samples were collected between the dates of 2019-04-03 and 2019-08-27
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	286745
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	3
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 3 of 4 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-05-30
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	287026
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2018-05-14
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	287026
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473).
Temporal Representation:	The samples were collected between the dates of 2013-05-09 and 2013-05-09
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	277906
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence).
Temporal Representation:	The samples were collected between the dates of 2019-04-23 and 2019-07-23
Environmental Conditions:	Spatial Representation:	The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473).
Temporal Representation:	The samples were collected between the dates of 2013-05-09 and 2013-05-09
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286910
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	6
Number of Exceedances:	4
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 4 of 6 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-08-27
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286758
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	277925
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473).
Temporal Representation:	The samples were collected between the dates of 2013-05-09 and 2013-05-09
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	278443
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2019-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	277841
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	The samples were collected between the dates of 2012-05-30 and 2012-05-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd).
Temporal Representation:	The samples were collected between the dates of 2019-04-30 and 2019-04-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286745
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	3
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 3 of 4 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-05-30
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286861
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471).
Temporal Representation:	The samples were collected between the dates of 2013-05-22 and 2013-05-22
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286988
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	277499
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Ammonia as N.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference:	Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence).
Temporal Representation:	The samples were collected between the dates of 2019-04-23 and 2019-07-23
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 154554, Eutrophication Region 2      Arroyo Mocho
LOE ID:	277901
Pollutant:	Nitrogen, ammonia (Total Ammonia)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the wat" width="33%">Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	The samples were collected between the dates of 2012-05-30 and 2012-05-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	28967
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	12
Number of Exceedances:	4
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Comprehensive water quality assessment was conducted at Arroyo Mocho Creek watershed as part of SWAMP assessment in 2004 and 2005. Continuous field monitoring of temperature, dissolved oxygen, pH, and specific conductance to determine temporal variability in basic water quality at one or two locations. The pH ranged from 7.0 to 9.2 and varied with season. The pH exceeded the maximum of 8.5 four times (9.2, 9.1, 8.8, 8.6) in all three (spring, summer, winter) seasons. The pH did not go below the minimum during any sampling event.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	pH was measured at two sites in summer 2004 and at five sites in spring 2004 and winter 2005 located within the Arroyo Mocho watershed that are representative of the entire watershed.
Temporal Representation:	At all locations the SWAMP performed continuous monitoring of pH at 15 minute intervals lasting 7-13 days during spring (April 2004), summer dry season (August 2004), and winter wet season (February 2005).
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	287006
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.).
Temporal Representation:	The samples were collected between the dates of 2015-05-20 and 2015-05-20
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

er quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 278516   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 278752   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 278061   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-24 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 278286   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection). Temporal Representation: The samples were collected between the dates of 2019-04-24 and 2019-05-30 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 278401   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 277903   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 278753   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 278459   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 3 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence). Temporal Representation: The samples were collected between the dates of 2019-04-23 and 2019-07-23 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 278081   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-03 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 278489   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 278808   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471). Temporal Representation: The samples were collected between the dates of 2013-05-22 and 2013-05-22 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 278817   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.). Temporal Representation: The samples were collected between the dates of 2015-05-20 and 2015-05-20 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 277682   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)). Temporal Representation: The samples were collected between the dates of 2019-04-24 and 2019-04-24 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 278773   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna). Temporal Representation: The samples were collected between the dates of 2014-05-07 and 2014-05-07 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 278358   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 278754   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd). Temporal Representation: The samples were collected between the dates of 2019-06-17 and 2019-06-17 Environmental Conditions: QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 278750   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473). Temporal Representation: The samples were collected between the dates of 2013-05-09 and 2013-05-09 Environmental Conditions: QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan. QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 278421   Pollutant: Nitrogen, ammonia (Total Ammonia) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document. Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 286760   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2019-06-05 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 286989   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 2 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct). Temporal Representation: The samples were collected between the dates of 2018-05-08 and 2019-05-08 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 286742   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout). Temporal Representation: The samples were collected between the dates of 2019-05-09 and 2019-05-09 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 286741   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley). Temporal Representation: The samples were collected between the dates of 2019-04-03 and 2019-04-03 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 287068   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 1   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: Non-SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd). Temporal Representation: The samples were collected between the dates of 2017-06-12 and 2017-06-12 Environmental Conditions: QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan. QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 286887   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Cold Freshwater Habitat   Number of Samples: 1 Number of Exceedances: 0   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH. Data Reference: Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.   SWAMP Data: SWAMP   Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31). Temporal Representation: The samples were collected between the dates of 2018-05-14 and 2018-05-14 Environmental Conditions: QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.. QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.  

Line of Evidence (LOE) for Decision ID 154554, Eutrophication	Region 2
Arroyo Mocho

  LOE ID: 28967   Pollutant: pH LOE Subgroup: Pollutant-Water Matrix: Water Fraction: None   Beneficial Use: Warm Freshwater Habitat   Number of Samples: 12 Number of Exceedances: 4   Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Comprehensive water quality assessment was conducted at Arroyo Mocho Creek watershed as part of SWAMP assessment in 2004 and 2005. Continuous field monitoring of temperature, dissolved oxygen, pH, and specific conductance to determine temporal variability in basic water quality at one or two locations. The pH ranged from 7.0 to 9.2 and varied with season. The pH exceeded the maximum of 8.5 four times (9.2, 9.1, 8.8, 8.6) in all three (spring, summer, winter) seasons. The pH did not go below the minimum during any sampling event. Data Reference: Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment   SWAMP Data: SWAMP   Water Quality Objective/Criterion: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)   Evaluation Guideline: Guideline Reference:   Spatial Representation: pH was measured at two sites in summer 2004 and at five sites in spring 2004 and winter 2005 located within the Arroyo Mocho watershed that are representative of the entire watershed. Temporal Representation: At all locations the SWAMP performed continuous monitoring of pH at 15 minute intervals lasting 7-13 days during spring (April 2004), summer dry season (August 2004), and winter wet season (February 2005). Environmental Conditions: QAPP Information: All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002). QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)  

DECISION ID	141767	Region 2
Arroyo Mocho

Pollutant:	Toxicity
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for listing under section 3.6 of the Listing Policy. Under section 3.6 a single line of evidence is necessary to assess listing status. Ten lines of evidence are available in the administrative record to assess this pollutant. This water body experiences toxicity. Based on the readily available data for this water body, the weight of evidence indicates that there is sufficient justification available in favor of adding this water segment-pollutant combination to the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data concerning current conditions and supporting the listing decision satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. Three out of seven water samples exhibited water toxicity. The number of samples with detected water toxicity exceeds the allowable frequency listed in Table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:

Line of Evidence (LOE) for Decision ID 141767, Toxicity Region 2      Arroyo Mocho
LOE ID:	268690
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	0 of the 1 samples collected by BASMAA RMC Monitoring in WY2012 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Survival, Hyalella azteca for Growth (wt/surv indiv).
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00100 ( Arroyo Mocho_BA_2012-204R00100 ).
Temporal Representation:	The samples were collected between the dates of 2012-07-25 and 2012-07-25.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141767, Toxicity Region 2      Arroyo Mocho
LOE ID:	268608
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	1 of the 2 samples collected by BASMAA RMC Monitoring in WY2014 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Ceriodaphnia dubia for Survival, Selenastrum capricornutum for Total Cell Count, Pimephales promelas for Survival, Pimephales promelas for Biomass (wt/orig indiv), Ceriodaphnia dubia for Young/female, Hyalella azteca for Survival. The following tests exhibited toxicity: Selenastrum capricornutum for Total Cell Count on 2014-07-23.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00292 ( Arroyo Mocho just upstream of confluence with Arroyo de la Laguna ).
Temporal Representation:	The samples were collected between the dates of 2014-03-29 and 2014-07-23.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141767, Toxicity Region 2      Arroyo Mocho
LOE ID:	268682
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	0 of the 1 samples collected by BASMAA RMC Monitoring in WY2012 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Survival, Hyalella azteca for Growth (wt/surv indiv).
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00100 ( Arroyo Mocho_BA_2012-204R00100 ).
Temporal Representation:	The samples were collected between the dates of 2012-07-25 and 2012-07-25.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141767, Toxicity Region 2      Arroyo Mocho
LOE ID:	268662
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	0 of the 1 samples collected by BASMAA RMC Monitoring in WY2014 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Growth (wt/surv indiv), Hyalella azteca for Survival.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00292 ( Arroyo Mocho just upstream of confluence with Arroyo de la Laguna ).
Temporal Representation:	The samples were collected between the dates of 2014-07-23 and 2014-07-23.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141767, Toxicity Region 2      Arroyo Mocho
LOE ID:	268610
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	1 of the 2 samples collected by BASMAA RMC Monitoring in WY2012 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Pimephales promelas for Biomass (wt/orig indiv), Selenastrum capricornutum for Total Cell Count, Ceriodaphnia dubia for Young/female, Ceriodaphnia dubia for Survival, Pimephales promelas for Survival, Hyalella azteca for Survival. The following tests exhibited toxicity: Pimephales promelas for Survival on 2012-03-14.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00100 ( Arroyo Mocho_BA_2012-204R00100 ).
Temporal Representation:	The samples were collected between the dates of 2012-03-14 and 2012-07-25.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141767, Toxicity Region 2      Arroyo Mocho
LOE ID:	268670
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	1 of the 2 samples collected by BASMAA RMC Monitoring in WY2014 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Ceriodaphnia dubia for Survival, Selenastrum capricornutum for Total Cell Count, Pimephales promelas for Survival, Pimephales promelas for Biomass (wt/orig indiv), Ceriodaphnia dubia for Young/female, Hyalella azteca for Survival. The following tests exhibited toxicity: Selenastrum capricornutum for Total Cell Count on 2014-07-23.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00292 ( Arroyo Mocho just upstream of confluence with Arroyo de la Laguna ).
Temporal Representation:	The samples were collected between the dates of 2014-03-29 and 2014-07-23.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141767, Toxicity Region 2      Arroyo Mocho
LOE ID:	268621
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	0 of the 1 samples collected by BASMAA RMC Monitoring in WY2014 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Growth (wt/surv indiv), Hyalella azteca for Survival.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00292 ( Arroyo Mocho just upstream of confluence with Arroyo de la Laguna ).
Temporal Representation:	The samples were collected between the dates of 2014-07-23 and 2014-07-23.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141767, Toxicity Region 2      Arroyo Mocho
LOE ID:	28994
Pollutant:	Toxicity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	3
Number of Exceedances:	1
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	Three samples were collected in 2005 to evaluate water toxicity at two monitoring locations in Arroyo Mocho watershed. The toxicity tests included survival and reproduction of Ceriodaphnia, survival and growth of fathead minnow, and growth of Selenastrum. Ceriodaphnia growth was significantly lower than the control in one of three samples (dry season sample). Growth was 69.4 percent of the control for this sample.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Water toxicity was evaluated according to the SWAMP methodology. The U.S.EPA whole effluent toxicity protocol (U.S.EPA 1994) was used to test the effect of water samples on three freshwater test organisms. Statistical evaluation (alpha = 0.05) and a default threshold of 80% of the control value were used to establish whether water exhibited significant toxicity adversely impacting aquatic organisms.
Guideline Reference:	Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. EPA/600/4-91/002. Third Edition. July 1994
Guideline Reference:	Revised approach to toxicity test acceptability criteria using a statistical performance assessment. Environmental Toxicology and Chemistry, vol. 16, No. 6, pp 1322¿1329
Spatial Representation:	Data were collected at one sampling location, AMO070, located above Vulcan Bridge Zone 7, representing the Arroyo Mocho Creek.
Temporal Representation:	SWAMP samples were collected during wet (January), spring (April), and dry (June) seasons of 2005.
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB, 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141767, Toxicity Region 2      Arroyo Mocho
LOE ID:	28832
Pollutant:	Sediment Toxicity
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Toxicity testing of sediments
Data Used to Assess Water Quality:	Data used to evaluate sediment toxicity comprise one sediment sample collected by the SWAMP in 2005. No toxicity or adverse affects were exhibited for Hyallela azteca.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances that are lethal to or that produce other detrimental responses in aquatic organisms. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:	Sediment toxicity was evaluated according to the SWAMP methodology. Sample toxicity was determined by comparing mean organism response in samples and in negative controls. Statistical evaluation (alpha = 0.05) and a default threshold of 80% of the control value were used to establish whether the sediment exhibited significant toxicity adversely impacting aquatic organisms.
Guideline Reference:	Revised approach to toxicity test acceptability criteria using a statistical performance assessment. Environmental Toxicology and Chemistry, vol. 16, No. 6, pp 1322¿1329
Spatial Representation:	One sediment sample was collected at a "watershed integrator" site located close to the mouth of Arroyo Mocho watershed (above Vulcan Bridge at zone 7).
Temporal Representation:	Sample was collected in April of 2005.
Environmental Conditions:
QAPP Information:	Samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141767, Toxicity Region 2      Arroyo Mocho
LOE ID:	268650
Pollutant:	Toxicity
LOE Subgroup:	Toxicity
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	TOXICITY TESTING
Data Used to Assess Water Quality:	1 of the 2 samples collected by BASMAA RMC Monitoring in WY2012 for Arroyo Mocho exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Pimephales promelas for Biomass (wt/orig indiv), Selenastrum capricornutum for Total Cell Count, Ceriodaphnia dubia for Young/female, Ceriodaphnia dubia for Survival, Pimephales promelas for Survival, Hyalella azteca for Survival. The following tests exhibited toxicity: Pimephales promelas for Survival on 2012-03-14.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:	The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference:	Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
Spatial Representation:	The samples were collected at monitoring site: 204R00100 ( Arroyo Mocho_BA_2012-204R00100 ).
Temporal Representation:	The samples were collected between the dates of 2012-03-14 and 2012-07-25.
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan

DECISION ID	141759	Region 2
Arroyo Mocho

Pollutant:	pH
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant
Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence are available in the administrative record to assess this pollutant. Twenty-three of the sixty-three samples exceed the Basin Plan objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Twenty-three of the sixty-three samples exceed the Basin Plan objective and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
State Board Review of Regional Board Conclusion and Recommendation:
State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
Listing Extent:	Elevated pH in Arroyo Mocho is likely due to nuisance algae growth. See listing decision for eutrophication (decision ID 154554).

Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	287068
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01497 (Arroyo Mocho 80 m east of Arroyo Rd).
Temporal Representation:	The samples were collected between the dates of 2017-06-12 and 2017-06-12
Environmental Conditions:
QAPP Information:	EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s):	BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286901
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R04251 (Arroyo Mocho approx 150m east of Santa Rita Rd).
Temporal Representation:	The samples were collected between the dates of 2019-06-17 and 2019-06-17
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	287205
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	12
Number of Exceedances:	2
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 2 of 12 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204ALP020 (Arroyo Las Positas at El Chorro).
Temporal Representation:	The samples were collected between the dates of 2018-05-16 and 2019-08-26
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	287034
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO100 (Wente Street (Concannon St.)).
Temporal Representation:	The samples were collected between the dates of 2019-04-02 and 2019-04-24
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286989
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO140 (Arroyo Mocho directly US of South Bay Aqueduct).
Temporal Representation:	The samples were collected between the dates of 2018-05-08 and 2019-05-08
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	287331
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	7
Number of Exceedances:	5
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 5 of 7 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204TASS01 (Tassajara Creek directly upstream of Arroyo Mocho confluence).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-08-27
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286737
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00292 (Arroyo Mocho just upstream of confluence with Arroyo de la Laguna).
Temporal Representation:	The samples were collected between the dates of 2014-05-07 and 2014-05-07
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286742
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO130 (Arroyo Mocho at directly d/s of South Bay Aqueduct turnout).
Temporal Representation:	The samples were collected between the dates of 2019-05-09 and 2019-05-09
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286746
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	5
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO190 (Arroyo Mocho at 22021 Mines Road).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-07-24
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286741
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO080 (Madeiros Parkway at Stanley).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-04-03
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286760
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO180 (Hetch Hetchy).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2019-06-05
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286887
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO195 (Arroyo Mocho at mile marker 16.31).
Temporal Representation:	The samples were collected between the dates of 2018-05-14 and 2018-05-14
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	287026
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00473 (Arroyo Mocho near Chateau Way-204R00473).
Temporal Representation:	The samples were collected between the dates of 2013-05-09 and 2013-05-09
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286910
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	6
Number of Exceedances:	4
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 4 of 6 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO030 (Arroyo Mocho directly downstream of Tassajara Creek confluence).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-08-27
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286758
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2019 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01241 (Arroyo Mocho approx 1200m upstream of Concannon Blvd).
Temporal Representation:	The samples were collected between the dates of 2019-04-30 and 2019-04-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286745
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	4
Number of Exceedances:	3
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed SWAMP RWB2 Monitoring data for Arroyo Mocho to determine beneficial use support and results are as follows: 3 of 4 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204AMO165 (Arroyo Mocho directly upstream of Mines Rd and Del Valle Rd intersection).
Temporal Representation:	The samples were collected between the dates of 2019-04-03 and 2019-05-30
Environmental Conditions:
QAPP Information:	SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s):	This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286861
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for Arroyo Mocho to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01471 (Arroyo Mocho upstream of Santa Rita Rd. -204R01471).
Temporal Representation:	The samples were collected between the dates of 2013-05-22 and 2013-05-22
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	286988
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2012 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R00100 (Arroyo Mocho_BA_2012-204R00100).
Temporal Representation:	The samples were collected between the dates of 2012-05-30 and 2012-05-30
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	28967
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	12
Number of Exceedances:	4
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Comprehensive water quality assessment was conducted at Arroyo Mocho Creek watershed as part of SWAMP assessment in 2004 and 2005. Continuous field monitoring of temperature, dissolved oxygen, pH, and specific conductance to determine temporal variability in basic water quality at one or two locations. The pH ranged from 7.0 to 9.2 and varied with season. The pH exceeded the maximum of 8.5 four times (9.2, 9.1, 8.8, 8.6) in all three (spring, summer, winter) seasons. The pH did not go below the minimum during any sampling event.
Data Reference:	Data collected by the Surface Water Ambient Monitoring Program, San Francisco Bay Regional Water Quality Control Board. Years 4 and 5 Assessment
SWAMP Data:	SWAMP
Water Quality Objective/Criterion:	The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	pH was measured at two sites in summer 2004 and at five sites in spring 2004 and winter 2005 located within the Arroyo Mocho watershed that are representative of the entire watershed.
Temporal Representation:	At all locations the SWAMP performed continuous monitoring of pH at 15 minute intervals lasting 7-13 days during spring (April 2004), summer dry season (August 2004), and winter wet season (February 2005).
Environmental Conditions:
QAPP Information:	All samples were collected and analyzed using procedures comparable with the SWAMP Quality Assurance Management Plan (SWRCB 2002).
QAPP Information Reference(s):	Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 141759, pH Region 2      Arroyo Mocho
LOE ID:	287006
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Cold Freshwater Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality:	Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Arroyo Mocho to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference:	Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
SWAMP Data:	Non-SWAMP
Water Quality Objective/Criterion:	Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.9 pH states: The pH shall not be depressed below 6.5 nor raised above 8.5. This encompasses the pH range usually found in waters within the basin. Controllable water quality factors shall not cause changes greater than 0.5 units in normal ambient pH levels.
Objective/Criterion Reference:	Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	The samples were collected at 1 monitoring site: 204R01828 (Arroyo Mocho approx 300 m downstream of Hopyard Rd.).
Temporal Representation:	The samples were collected between the dates of 2015-05-20 and 2015-05-20
Environmental Conditions:
QAPP Information:	EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s):	Creek Status Monitoring Program Quality Assurance Project Plan