| Water Body Name: | Bishop Creek B-1 Drain |
| Water Body ID: | CAR6032028020171227020994 |
| Water Body Type: | River & Stream |
DECISION ID |
169237 |
Region 6 |
Bishop Creek B-1 Drain |
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| Pollutant: | Indicator Bacteria |
| Final Listing Decision: | Do Not Delist from 303(d) list (associated with a USEPA accepted Advanced Restoration Plan) |
| Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2018) |
| Revision Status | Revised |
| Sources: | A Source Unknown |
| TMDL Name: | Bishop Creek Bacteria Advance Restoration Plan (Vision Plan) |
| TMDL Project Code: | 1422 |
| 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. Three lines of evidence are available in the administrative record to assess this pollutant. 109 of the 241 samples exceed the 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, since the Lahontan Region's fecal coliform objective was removed from the Basin Plan in 2024). 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. One hundred and nine of 241 samples exceeded the objective 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: | |
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| LOE ID: | 336734 | ||||
| Pollutant: | Escherichia coli (E. coli) | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | STV | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 52 | ||||
| Number of Exceedances: | 26 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed Eastern Sierra Fecal Indicator Bacteria Study data for Bishop Creek B-1 Drain to determine beneficial use support and the results are as follows: 26 of the 52 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly. | ||||
| Data Reference: | WQ from the MBC Fecal indicator study in the Eastern Sierra for the 2026 Integrated Report in Region 6 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | The bacteria water quality objective to protect the REC-1 beneficial use in waters other than Lake Thaoe, where the salinity is less than 1 parts per thousand 95 percent or more of the time applies a statistical threshold value to E. coli of 320 cfu/100 mL, not to be exceeded by more than 10 percent of samples within a calendar month (ISWEBE 2018). | ||||
| 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): BC 22 (Bishop Creek Station 22). | ||||
| Temporal Representation: | The samples were collected between the days of 2015-06-03 and 2022-07-20 . | ||||
| Environmental Conditions: | |||||
| QAPP Information: | MBC FIB Bacteria QAPP | ||||
| QAPP Information Reference(s): | MBC Aquatic Sciences - FIB Bacteria QAPP - Eastern Sierra Fecal Indicator Bacteria Study - 402598 | ||||
| QAPP Information Reference(s): | MBC Aquatic Sciences - QAPP FIB Study V3. - Eastern Sierra Fecal Indicator Bacteria Study - 402641 | ||||
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| LOE ID: | 99797 | ||||
| Pollutant: | Escherichia coli (E. coli) | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 14 | ||||
| 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 Bishop Creek B-1 Drain to determine beneficial use support and the results are as follows: 4 of the 14 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): 603BSPB23 | ||||
| Temporal Representation: | The samples were collected between the days of 2014-05-14 and 2015-10-13 . | ||||
| 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 | ||||
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| LOE ID: | 336648 | ||||
| Pollutant: | Escherichia coli (E. coli) | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | GeoMean | ||||
| Beneficial Use: | Water Contact Recreation | ||||
| Number of Samples: | 175 | ||||
| Number of Exceedances: | 79 | ||||
| Data and Information Type: | PATHOGEN MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed Eastern Sierra Fecal Indicator Bacteria Study data for Bishop Creek B-1 Drain to determine beneficial use support and the results are as follows: 79 of the 175 samples exceeded the geomean water quality threshold for E. coli. This is a six week rolling geomean that is calculated weekly. | ||||
| Data Reference: | WQ from the MBC Fecal indicator study in the Eastern Sierra for the 2026 Integrated Report in Region 6 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | The bacteria water quality objective to protect the REC-1 beneficial use for waters other than Lake Tahoe, where the salinity is equal to or less than 1 part per thousand 95 percent or more of the time applies a rolling six-week geometric mean of E. coli, not to exceed 100 cfu/100 mL (ISWEBE 2018). | ||||
| 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): BC 22 (Bishop Creek Station 22). | ||||
| Temporal Representation: | The samples were collected between the days of 2015-06-03 and 2022-07-20 . | ||||
| Environmental Conditions: | |||||
| QAPP Information: | MBC FIB Bacteria QAPP | ||||
| QAPP Information Reference(s): | MBC Aquatic Sciences - FIB Bacteria QAPP - Eastern Sierra Fecal Indicator Bacteria Study - 402598 | ||||
| QAPP Information Reference(s): | MBC Aquatic Sciences - QAPP FIB Study V3. - Eastern Sierra Fecal Indicator Bacteria Study - 402641 | ||||