| Water Body Name: | Robinson Creek (Twin Lakes to Hwy 395) |
| Water Body ID: | CAR6303005020020117085757 |
| Water Body Type: | River & Stream |
DECISION ID |
172164 |
Region 6 |
Robinson Creek (Twin Lakes to Hwy 395) |
||
| Pollutant: | Indicator Bacteria |
| Final Listing Decision: | Delist from 303(d) list (being addressed by action other than TMDL) |
| Last Listing Cycle's Final Listing Decision: | Do Not Delist from 303(d) list (being addressed with action other than TMDL)(2018) |
| Revision Status | Revised |
| Reason for Delisting: | Applicable WQS attained; due to change in WQS |
| Expected Attainment Date: | 2028 |
| Implementation Action Other than TMDL: | This listing is being addressed through the implementation of management practices for livestock grazing under the General Conditional Waiver of Waste Discharge Requirements for Grazing Operations in the East Walker River Watershed (Bridgeport Valley and Tributaries) of the Lahontan Region. |
| 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 4.3 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Two of 2 E. coli geomean samples and 8 of 97 E. coli Statistical Threshold Value (STV) samples exceed the water quality objective. (Fecal coliform lines of evidence used in previous indicator bacteria decisions in the Lahontan Region have been removed from decisions, starting in the 2026 Integrated Report, because the Lahontan Region's fecal coliform objective was removed from the Basin Plan in 2024). In 2023 the Lahontan Water Board approved Resolution R6T-2023-0006: Renewal of General Condition Waiver of Waste Discharge Requirements for Grazing Operations in the East Walker River Watershed (Bridgeport Valley and Tributaries) of the Lahontan Region. This waiver is designed to improve water quality in the Bridgeport Valley, including this waterbody. The waiver expects water quality to attain WQOs by 2028. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for removing this water segment-pollutant combination from the CWA section 303(d) List. Removing this water segment-pollutant combination from the CWA section 303(d) List is consistent with several factors described in the following paragraphs from the Listing Policy section 4: -All listings of water segments shall be removed from the section 303(d) list if the listing was based on faulty data, and it is demonstrated that the listing would not have occurred in the absence of such faulty data. Faulty data include, but are not limited to, typographical errors, improper quality assurance/quality control procedures, or limitations related to the analytical methods that would lead to improper conclusions regarding the water quality status of the segment. If objectives or standards have been revised and the site or water meets water quality standards, the water segment shall be removed from the section 303(d) list. The listing of a segment shall be reevaluated if the water quality standard has been changed. This conclusion is based on the staff findings that: 1. Change of the water quality standards: The basis for listing this waterbody for indicator bacteria was exceedances of the fecal coliform water quality objective. The Region 6 fecal coliform water quality objective was removed has been removed from the Lahontan Basin Plan. 2. Faulty Data: Fecal coliform data previously used to support this listing are considered faulty data because fecal coliform bacteria do not adequately indicate risk to the MUN/REC-1 use and assessing such data would lead to improper conclusions regarding the water quality status of the segment. Fecal coliform has not been a USEPA recommended indicator bacteria for assessing water-contact recreational uses since 1986. Adoption of the statewide E. coli-based REC-1 water quality objectives is a revision of indicator bacteria to assess the REC-1 beneficial use and fecal coliform is no longer used. Additionally, assessment of fecal coliform data, which was originally used to list this waterbody with the assessment of MUN using fecal coliform data does not correspond to a water quality objective in the Lahontan Basin Plan, so associating past data with MUN is no longer appropriate. 3. The waterbody's bacteriological water quality will be assessed using E. coli or other more representative measures, should such data be available in the future. 4. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 5. The data used does not satisfy the data quantity requirements of section 6.1.5 of the Policy. Only two geometric mean E. coli samples were available, and this is insufficient information 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. 6. Two of 2 E. coli geomean samples and 8 of 97 E. coli Statistical Threshold Value (STV) samples exceed the water quality objective for the REC-1 beneficial use and this does not exceed the allowable frequency listed in Table 4.2 of the Listing Policy. 7. Pursuant to section 4.11 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 removed from the section 303(d) list because the original basis for listing was flawed. |
| State Board Review of Regional Board Conclusion and Recommendation: | 4. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 5. The data used does not satisfy the data quantity requirements of section 6.1.5 of the Policy. Only two geometric mean E. coli samples were available, and this is insufficient information 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. 6. Two of 2 E. coli geomean samples and 8 of 97 E. coli Statistical Threshold Value (STV) samples exceed the water quality objective for the REC-1 beneficial use and this does not exceed the allowable frequency listed in Table 4.2 of the Listing Policy. 7. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. |
| State Board Decision Recommendation: | After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board. |
| Listing Extent: | |
|
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| LOE ID: | 99829 | ||||
| Pollutant: | Escherichia coli (E. coli) | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 2 | ||||
| Number of Exceedances: | 2 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed SWAMP RWB6 Monitoring data for Robinson Creek (Twin Lakes to Hwy 395) to determine beneficial use support and the results are as follows: 2 of the 2 samples exceeded the geomean water quality standard for E. coli. This is a six week rolling geomean that is calculated weekly. | ||||
| Data Reference: | Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for the SWAMP RWB6 Monitoring (tissue and water). | ||||
| SWAMP Data: | SWAMP | ||||
| Water Quality Objective/Criterion: | The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a six-week rolling GEOMETRIC MEAN (GM) of Escherichia coli (E. coli) not to exceed 100 colony forming units per 100 milliliters (cfu/100 mL) (calculated weekly). | ||||
| Objective/Criterion Reference: | Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The samples were collected at 2 monitoring site(s), station(s): 630RBS007, 630RBS008 | ||||
| Temporal Representation: | The samples were collected between the days of 2011-06-13 and 2013-07-10 . | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program | ||||
| QAPP Information Reference(s): | |||||
DECISION ID |
172164 |
Region 6 |
|||
Robinson Creek (Twin Lakes to Hwy 395) |
|||||
| Pollutant: | Indicator Bacteria | ||||
| Final Listing Decision: | Delist from 303(d) list (being addressed by action other than TMDL) | ||||
| Last Listing Cycle's Final Listing Decision: | Do Not Delist from 303(d) list (being addressed with action other than TMDL)(2018) | ||||
| Revision Status | Revised | ||||
| Reason for Delisting: | Applicable WQS attained; due to change in WQS | ||||
| Expected Attainment Date: | 2028 | ||||
| Implementation Action Other than TMDL: | This listing is being addressed through the implementation of management practices for livestock grazing under the General Conditional Waiver of Waste Discharge Requirements for Grazing Operations in the East Walker River Watershed (Bridgeport Valley and Tributaries) of the Lahontan Region. | ||||
| 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 4.3 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Two of 2 E. coli geomean samples and 8 of 97 E. coli Statistical Threshold Value (STV) samples exceed the water quality objective. (Fecal coliform lines of evidence used in previous indicator bacteria decisions in the Lahontan Region have been removed from decisions, starting in the 2026 Integrated Report, because the Lahontan Region's fecal coliform objective was removed from the Basin Plan in 2024). In 2023 the Lahontan Water Board approved Resolution R6T-2023-0006: Renewal of General Condition Waiver of Waste Discharge Requirements for Grazing Operations in the East Walker River Watershed (Bridgeport Valley and Tributaries) of the Lahontan Region. This waiver is designed to improve water quality in the Bridgeport Valley, including this waterbody. The waiver expects water quality to attain WQOs by 2028. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for removing this water segment-pollutant combination from the CWA section 303(d) List. Removing this water segment-pollutant combination from the CWA section 303(d) List is consistent with several factors described in the following paragraphs from the Listing Policy section 4: -All listings of water segments shall be removed from the section 303(d) list if the listing was based on faulty data, and it is demonstrated that the listing would not have occurred in the absence of such faulty data. Faulty data include, but are not limited to, typographical errors, improper quality assurance/quality control procedures, or limitations related to the analytical methods that would lead to improper conclusions regarding the water quality status of the segment. If objectives or standards have been revised and the site or water meets water quality standards, the water segment shall be removed from the section 303(d) list. The listing of a segment shall be reevaluated if the water quality standard has been changed. This conclusion is based on the staff findings that: 1. Change of the water quality standards: The basis for listing this waterbody for indicator bacteria was exceedances of the fecal coliform water quality objective. The Region 6 fecal coliform water quality objective was removed has been removed from the Lahontan Basin Plan. 2. Faulty Data: Fecal coliform data previously used to support this listing are considered faulty data because fecal coliform bacteria do not adequately indicate risk to the MUN/REC-1 use and assessing such data would lead to improper conclusions regarding the water quality status of the segment. Fecal coliform has not been a USEPA recommended indicator bacteria for assessing water-contact recreational uses since 1986. Adoption of the statewide E. coli-based REC-1 water quality objectives is a revision of indicator bacteria to assess the REC-1 beneficial use and fecal coliform is no longer used. Additionally, assessment of fecal coliform data, which was originally used to list this waterbody with the assessment of MUN using fecal coliform data does not correspond to a water quality objective in the Lahontan Basin Plan, so associating past data with MUN is no longer appropriate. 3. The waterbody's bacteriological water quality will be assessed using E. coli or other more representative measures, should such data be available in the future. 4. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 5. The data used does not satisfy the data quantity requirements of section 6.1.5 of the Policy. Only two geometric mean E. coli samples were available, and this is insufficient information 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. 6. Two of 2 E. coli geomean samples and 8 of 97 E. coli Statistical Threshold Value (STV) samples exceed the water quality objective for the REC-1 beneficial use and this does not exceed the allowable frequency listed in Table 4.2 of the Listing Policy. 7. Pursuant to section 4.11 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 removed from the section 303(d) list because the original basis for listing was flawed. | ||||
| State Board Review d> | Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program | ||||
|
|||||
| LOE ID: | 99861 | ||||
| Pollutant: | Escherichia coli (E. coli) | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 24 | ||||
| Number of Exceedances: | 1 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed Eastern Sierra Ambient Monitoring data for Robinson Creek (Twin Lakes to Hwy 395) to determine beneficial use support and the results are as follows: 1 of the 24 samples exceeded the Statistical Threshold Value (STV) water quality standard for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly. | ||||
| Data Reference: | Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for Eastern Sierra Ambient Monitoring. | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a STATISTICAL THRESHOLD VALUE (STV) of 320 cfu/100 mL not to be exceeded more than 10 percent of the time (calculated monthly). | ||||
| Objective/Criterion Reference: | Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The samples were collected at 4 monitoring site(s), station(s): 630RBS007, 630RBS008, RBS.04, RBS.05 | ||||
| Temporal Representation: | The samples were collected between the days of 2012-08-14 and 2013-10-16 . | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Quality Assurance Project Plan Sierra Nevada Aquatic Research Laboratory Center for Eastern Sierra Aquatic Microbial Ecology | ||||
| QAPP Information Reference(s): | Quality Assurance Project Plan Sierra Nevada Aquatic Research Laboratory Center for Eastern Sierra Aquatic Microbial Ecology (SNARL - CESAME) | ||||
|
|||||
| LOE ID: | 99972 | ||||
| Pollutant: | Escherichia coli (E. coli) | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 52 | ||||
| Number of Exceedances: | 4 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed RWB6_BACT_Monitoring data for Robinson Creek (Twin Lakes to Hwy 395) to determine beneficial use support and the results are as follows: 4 of the 52 samples exceeded the Statistical Threshold Value (STV) water quality standard for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly. | ||||
| Data Reference: | Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for Regional Water Board 6 Bacteria Monitoring. | ||||
| SWAMP Data: | SWAMP | ||||
| Water Quality Objective/Criterion: | The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a STATISTICAL THRESHOLD VALUE (STV) of 320 cfu/100 mL not to be exceeded more than 10 percent of the time (calculated monthly). | ||||
| Objective/Criterion Reference: | Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The samples were collected at 4 monitoring site(s), station(s): 630RBS007, 630RBS008, RBS.03, RBS.05 | ||||
| Temporal Representation: | The samples were collected between the days of 2014-05-13 and 2015-10-15 . | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program | ||||
| QAPP Information Reference(s): | Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program | ||||
|
|||||
| LOE ID: | 99819 | ||||
| Pollutant: | Escherichia coli (E. coli) | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 21 | ||||
| Number of Exceedances: | 3 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed SWAMP RWB6 Monitoring data for Robinson Creek (Twin Lakes to Hwy 395) to determine beneficial use support and the results are as follows: 3 of the 21 samples exceeded the Statistical Threshold Value (STV) water quality standard for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly. | ||||
| Data Reference: | Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for the SWAMP RWB6 Monitoring (tissue and water). | ||||
| SWAMP Data: | SWAMP | ||||
| Water Quality Objective/Criterion: | The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a STATISTICAL THRESHOLD VALUE (STV) of 320 cfu/100 mL not to be exceeded more than 10 percent of the time (calculated monthly). | ||||
| Objective/Criterion Reference: | Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The samples were collected at 2 monitoring site(s), station(s): 630RBS007, 630RBS008 | ||||
| Temporal Representation: | The samples were collected between the days of 2011-06-13 and 2013-07-10 . | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program | ||||
| QAPP Information Reference(s): | Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program | ||||
|
|||||
| LOE ID: | 99829 | ||||
| Pollutant: | Escherichia coli (E. coli) | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 2 | ||||
| Number of Exceedances: | 2 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed SWAMP RWB6 Monitoring data for Robinson Creek (Twin Lakes to Hwy 395) to determine beneficial use support and the results are as follows: 2 of the 2 samples exceeded the geomean water quality standard for E. coli. This is a six week rolling geomean that is calculated weekly. | ||||
| Data Reference: | Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for the SWAMP RWB6 Monitoring (tissue and water). | ||||
| SWAMP Data: | SWAMP | ||||
| Water Quality Objective/Criterion: | The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a six-week rolling GEOMETRIC MEAN (GM) of Escherichia coli (E. coli) not to exceed 100 colony forming units per 100 milliliters (cfu/100 mL) (calculated weekly). | ||||
| Objective/Criterion Reference: | Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The samples were collected at 2 monitoring site(s), station(s): 630RBS007, 630RBS008 | ||||
| Temporal Representation: | The samples were collected between the days of 2011-06-13 and 2013-07-10 . | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program | ||||
| QAPP Information Reference(s): | Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program | ||||
|
|||||
| LOE ID: | 99861 | ||||
| Pollutant: | Escherichia coli (E. coli) | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 24 | ||||
| Number of Exceedances: | 1 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed Eastern Sierra Ambient Monitoring data for Robinson Creek (Twin Lakes to Hwy 395) to determine beneficial use support and the results are as follows: 1 of the 24 samples exceeded the Statistical Threshold Value (STV) water quality standard for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly. | ||||
| Data Reference: | Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for Eastern Sierra Ambient Monitoring. | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a STATISTICAL THRESHOLD VALUE (STV) of 320 cfu/100 mL not to be exceeded more than 10 percent of the time (calculated monthly). | ||||
| Objective/Criterion Reference: | Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The samples were collected at 4 monitoring site(s), station(s): 630RBS007, 630RBS008, RBS.04, RBS.05 | ||||
| Temporal Representation: | The samples were collected between the days of 2012-08-14 and 2013-10-16 . | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Quality Assurance Project Plan Sierra Nevada Aquatic Research Laboratory Center for Eastern Sierra Aquatic Microbial Ecology | ||||
| QAPP Information Reference(s): | Quality Assurance Project Plan Sierra Nevada Aquatic Research Laboratory Center for Eastern Sierra Aquatic Microbial Ecology (SNARL - CESAME) | ||||
|
|||||
| LOE ID: | 99972 | ||||
| Pollutant: | Escherichia coli (E. coli) | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 52 | ||||
| Number of Exceedances: | 4 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed RWB6_BACT_Monitoring data for Robinson Creek (Twin Lakes to Hwy 395) to determine beneficial use support and the results are as follows: 4 of the 52 samples exceeded the Statistical Threshold Value (STV) water quality standard for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly. | ||||
| Data Reference: | Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for Regional Water Board 6 Bacteria Monitoring. | ||||
| SWAMP Data: | SWAMP | ||||
| Water Quality Objective/Criterion: | The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a STATISTICAL THRESHOLD VALUE (STV) of 320 cfu/100 mL not to be exceeded more than 10 percent of the time (calculated monthly). | ||||
| Objective/Criterion Reference: | Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The samples were collected at 4 monitoring site(s), station(s): 630RBS007, 630RBS008, RBS.03, RBS.05 | ||||
| Temporal Representation: | The samples were collected between the days of 2014-05-13 and 2015-10-15 . | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program | ||||
| QAPP Information Reference(s): | Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program | ||||
|
|||||
| LOE ID: | 99819 | ||||
| Pollutant: | Escherichia coli (E. coli) | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 21 | ||||
| Number of Exceedances: | 3 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed SWAMP RWB6 Monitoring data for Robinson Creek (Twin Lakes to Hwy 395) to determine beneficial use support and the results are as follows: 3 of the 21 samples exceeded the Statistical Threshold Value (STV) water quality standard for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly. | ||||
| Data Reference: | Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for the SWAMP RWB6 Monitoring (tissue and water). | ||||
| SWAMP Data: | SWAMP | ||||
| Water Quality Objective/Criterion: | The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a STATISTICAL THRESHOLD VALUE (STV) of 320 cfu/100 mL not to be exceeded more than 10 percent of the time (calculated monthly). | ||||
| Objective/Criterion Reference: | Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | The samples were collected at 2 monitoring site(s), station(s): 630RBS007, 630RBS008 | ||||
| Temporal Representation: | The samples were collected between the days of 2011-06-13 and 2013-07-10 . | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program | ||||
| QAPP Information Reference(s): | Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program | ||||