| Water Body Name: | Calleguas Creek Reach 12 (was Conejo Creek/Arroyo Conejo North Fork on 1998 303d list), unnamed tributary at Olsen Road |
| Water Body ID: | CAR4036400020120313145457 |
| Water Body Type: | River & Stream |
DECISION ID |
96920 |
Region 4 |
Calleguas Creek Reach 12 (was Conejo Creek/Arroyo Conejo North Fork on 1998 303d list), unnamed tributary at Olsen Road |
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| Pollutant: | Cyanide |
| 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)(2016) |
| Revision Status | Original |
| 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. Under section 3.1 a single line of evidence is necessary to assess listing status.
1 line of evidence is available in the administrative record to assess this pollutant. 0 of 62 samples exceeded the CRITERIA. 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 of 62 samples exceeded the CRITERIA 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 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. |
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|||||
| LOE ID: | 83547 | ||||
| Pollutant: | Cyanide | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | Total | ||||
| Beneficial Use: | Warm Freshwater Habitat | ||||
| Number of Samples: | 31 | ||||
| Number of Exceedances: | 0 | ||||
| Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants) | ||||
| Data Used to Assess Water Quality: | None of the 31 samples exceeded the criteria of 5.2 ug/L. The reporting limit for one non-detect sample was excluded from the assessment because the reporting limit was greater than the criteria. | ||||
| Data Reference: | Data for various pollutants in Calleguas Creek Reach 10, Jan. 2005-Jun. 2010 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use. | ||||
| Objective/Criterion Reference: | Water Quality Control Plan Los Angeles Region R4 Basin Plan | ||||
| Evaluation Guideline: | California Toxics Rule (NTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The CTR for cyanide is 5.2 ug/L. | ||||
| Guideline Reference: | Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition | ||||
| Spatial Representation: | R-1 is the upstream of the discharge (Hill Canyon WWTP) sample site (Latitude (N) 34.21332, Longitude (W) 118.92149 and elev. at 87 m). | ||||
| Temporal Representation: | Samples are collected quarterly during the months of February, May, August, and November. Semi-annual sampling events in February and August, and an annual event takes place in August. | ||||
| Environmental Conditions: | Hill Canyon WWTP Discharges tertiary treated municipal and industrial wastewater into North Fork Arroyo Conejo (approximate coordinates: Latitude 34o 12' 38" North, Longitude 118o 55' 12" West). | ||||
| QAPP Information: | Samples are collected and analyzed in accordance with the City of Thousand Oaks Hill Canyon Wastewater Treatment Plant (Hill Canyon WWTP)located in Camarillo, to North Fork Arroyo Conejo, a water of the United States. The discharge is regulated under waste discharge requirements contained in Order No. 96-044, adopted by this Regional Board on June 10, 1996. Order No. 96-044 also serves as a permit under the National Pollutant Discharge Elimination System (NPDES No.CA0056294). | ||||
| QAPP Information Reference(s): | |||||
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| LOE ID: | 83548 | ||||
| Pollutant: | Cyanide | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | Total | ||||
| Beneficial Use: | Warm Freshwater Habitat | ||||
| Number of Samples: | 31 | ||||
| Number of Exceedances: | 0 | ||||
| Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants) | ||||
| Data Used to Assess Water Quality: | None of the 31 samples exceeded the criteria of 5.2 ug/L. The reporting limit for one non-detect sample was excluded from the assessment because the reporting limit was greater than the criteria. | ||||
| Data Reference: | Data for various pollutants in Calleguas Creek Reach 10, Jan. 2005-Jun. 2010 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use. | ||||
| Objective/Criterion Reference: | Water Quality Control Plan Los Angeles Region R4 Basin Plan | ||||
| Evaluation Guideline: | California Toxics Rule (NTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The CTR for cyanide is 5.2 ug/L. | ||||
| Guideline Reference: | Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition | ||||
| Spatial Representation: | R-2 is downstream (Latitude (N) 34.21139, Longitude (W) 118.92329 and elev. at 84m) of our discharge and consists of effluent and the water flowing from sample site R-1. | ||||
| Temporal Representation: | Samples are collected quarterly during the months of February, May, August, and November. Semi-annual sampling events in February and August, and an annual event takes place in August. | ||||
| Environmental Conditions: | Hill Canyon WWTP Discharges tertiary treated municipal and industrial wastewater into North Fork Arroyo Conejo (approximate coordinates: Latitude 34o 12' 38" North, Longitude 118o 55' 12" West). | ||||
| QAPP Information: | Samples are collected and analyzed in accordance with the City of Thousand Oaks Hill Canyon Wastewater Treatment Plant (Hill Canyon WWTP)located in Camarillo, to North Fork Arroyo Conejo, a water of the United States. The discharge is regulated under waste discharge requirements contained in Order No. 96-044, adopted by this Regional Board on June 10, 1996. Order No. 96-044 also serves as a permit under the National Pollutant Discharge Elimination System (NPDES No.CA0056294). | ||||
| QAPP Information Reference(s): | |||||
DECISION ID |
96921 |
Region 4 |
Calleguas Creek Reach 12 (was Conejo Creek/Arroyo Conejo North Fork on 1998 303d list), unnamed tributary at Olsen Road |
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| 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)(2016) |
| Revision Status | Original |
| 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. Under section 3.1 a single line of evidence are necessary to assess listing status.
1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. 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. 0 of 1 sample exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using 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 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. |
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| LOE ID: | 82674 | ||||
| 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: | The sample did not exceed the hardness based criteria calculate for lead. | ||||
| Data Reference: | RWB4 Stormwater Monitoring Council CY2008 CY2009 | ||||
| SWAMP Data: | SWAMP | ||||
| Water Quality Objective/Criterion: | Water Quality Control Plan, Los Angeles Region (LARWQCB 1994): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion. | ||||
| Objective/Criterion Reference: | Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The sample was collected at station 408BA0036 (North Fork Arroyo Conejo Random Site 36). | ||||
| Temporal Representation: | The sample was collected on 5/5/2008. | ||||
| Environmental Conditions: | |||||
| QAPP Information: | SWAMP QAPP (2008) was followed. | ||||
| QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan | ||||
DECISION ID |
96922 |
Region 4 |
Calleguas Creek Reach 12 (was Conejo Creek/Arroyo Conejo North Fork on 1998 303d list), unnamed tributary at Olsen Road |
||
| 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)(2016) |
| Revision Status | Original |
| 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. Under section 3.1 a single line of evidence are necessary to assess listing status.
1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the CRITERIA. 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. 0 of 1 sample exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using 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 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. |
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| LOE ID: | 82663 | ||||
| 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: | The sample did not exceed the hardness based criteria calculated for zinc. | ||||
| Data Reference: | RWB4 Stormwater Monitoring Council CY2008 CY2009 | ||||
| SWAMP Data: | SWAMP | ||||
| Water Quality Objective/Criterion: | Water Quality Control Plan, Los Angeles Region (LARWQCB 1994): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion. | ||||
| Objective/Criterion Reference: | Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | Sample was collected at station 408BA0036 (North Fork Arroyo Conejo Random Site 36). | ||||
| Temporal Representation: | The sample was collected on 5/5/2008. | ||||
| Environmental Conditions: | |||||
| QAPP Information: | SWAMP QAPP (2008) was followed. | ||||
| QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan | ||||