| Water Body Name: | Robinson Creek (Hwy 395 to Bridgeport Res) |
| Water Body ID: | CAR6303005020011214081721 |
| Water Body Type: | River & Stream |
DECISION ID |
172162 |
Region 6 |
Robinson Creek (Hwy 395 to Bridgeport Res) |
||
| 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: | Flaws in original listing |
| Expected Attainment Date: | 2028 |
| Implementation Action Other than TMDL: | This impairment is being addressed under the 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. |
| 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 of the Listing Policy. One line of evidence is available in the administrative record to assess this pollutant. One of 9 E. coli samples exceed the objective for the REC-1 beneficial use. (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 Water Quality Control Plan for the Lahontan Region (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. One of 9 E. coli samples exceed the objective for the REC-1 beneficial use and this does not exceed the allowable frequency listed in Table 3.2 or 4.2 of the listing policy. However not enough samples are available to assess beneficial use attainment. 4. 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. 5. 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: | |
| 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: | 100033 | ||||
| Pollutant: | Escherichia coli (E. coli) | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 9 | ||||
| Number of Exceedances: | 1 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed RWB6_BACT_Monitoring data for Robinson Creek (Hwy 395 to Bridgeport Res) to determine beneficial use support and the results are as follows: 1 of the 9 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 1 monitoring site(s), station(s): RBS.10 | ||||
| Temporal Representation: | The samples were collected between the days of 2014-06-03 and 2015-10-14 . | ||||
| 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 | ||||
DECISION ID |
172162 |
Region 6 |
Robinson Creek (Hwy 395 to Bridgeport Res) |
||
| 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: | Flaws in original listing |
| Expected Attainment Date: | 2028 |
| Implementation Action Other than TMDL: | This impairment is being addressed under the 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. |
| 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 of the Listing Policy. One line of evidence is available in the administrative record to assess this pollutant. One of 9 E. coli samples exceed the objective for the REC-1 beneficial use. (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 Water Quality Control Plan for the Lahontan Region (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. One of 9 E. coli samples exceed the objective for the REC-1 beneficial use and this does not exceed the allowable frequency listed in Table 3.2 or 4.2 of the listing policy. However not enough samples are available to assess beneficial use attainment. 4. 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. 5. 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: | |
| 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 ID: | 100033 | ||||
| Pollutant: | Escherichia coli (E. coli) | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 9 | ||||
| Number of Exceedances: | 1 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed RWB6_BACT_Monitoring data for Robinson Creek (Hwy 395 to Bridgeport Res) to determine beneficial use support and the results are as follows: 1 of the 9 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 1 monitoring site(s), station(s): RBS.10 | ||||
| Temporal Representation: | The samples were collected between the days of 2014-06-03 and 2015-10-14 . | ||||
| 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 | ||||