Final California 2020 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 6 - Lahontan Region

Water Body Name: Robinson Creek (Twin Lakes to Hwy 395)
Water Body ID: CAR6303005020020117085757
Water Body Type: River & Stream
 
DECISION ID
76458
Region 6     
Robinson Creek (Twin Lakes to Hwy 395)
 
Pollutant: Indicator Bacteria
Final Listing Decision: Do Not Delist from 303(d) list (being addressed with action other than TMDL)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (being addressed by action other than TMDL)(2016)
Revision Status Revised
Sources: Agricultural Water Diversion | Agriculture-grazing | Grazing-Related Sources | Natural Sources | Pasture Grazing-Riparian and/or Upland | Streambank Modification/Destabilization | Unknown Nonpoint Source
Expected Attainment Date: 2028
Implementation Action Other than TMDL: This listing is being addressed through the implementation of management practices for livestock grazing under Lahontan RWQCB Resolution R6T-2017-0033, 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 4.2 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status.

Twelve lines of evidence for a range of indicator bacteria assessed against the REC-1 and MUN beneficial uses are available in the administrative record to assess this pollutant. 2 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. 52 of 113 fecal coliform geomeans and 47 of 108 fecal coliform STV samples exceed the objective for the MUN 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.

In 2017 the Lahontan Water Board approved Resolution R6T-2017-0033, 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, of which mid-branch Buckeye Creek is a waterbody. The waiver expects water quality to attain WQOs by 2028.

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 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. 52 of 113 fecal coliform geomeans and 47 of 108 fecal coliform STV samples exceed the objective for the MUN beneficial use, and these sample sizes exceed 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.
 
 
Line of Evidence (LOE) for Decision ID 76458, Indicator Bacteria
Region 6     
Robinson Creek (Twin Lakes to Hwy 395)
 
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
 
Line of Evidence (LOE) for Decision ID 76458, Indicator Bacteria
Region 6     
Robinson Creek (Twin Lakes to Hwy 395)
 
LOE ID: 4635
 
Pollutant: Pathogens
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Water Contact Recreation
 
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 pre-2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Unspecified
Objective/Criterion Reference: Placeholder reference pre-2006 303(d)
 
Evaluation Guideline: Unspecified
Guideline Reference: Placeholder reference pre-2006 303(d)
 
Spatial Representation: Unspecified
Temporal Representation: Unspecified
Environmental Conditions: Unspecified
QAPP Information: Unspecified
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 76458, Indicator Bacteria
Region 6     
Robinson Creek (Twin Lakes to Hwy 395)
 
LOE ID: 27591
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 15
Number of Exceedances: 5
 
Data and Information Type: Water column surveys (e.g. fecal coliform)
Data Used to Assess Water Quality: Swauger Creek was placed on the Section 303(d) list in 2002 as a result of sampling in 2000 and 2001 by the U.S. Geological Survey. At least 5 of 16 monthly fecal coliform samples exceeded the 40 colonies per 100 mL limit. Fecal coliform counts ranged from 1 to 3600 colonies per 100 mL. Some of the sampling results were reported with a "K" code indicating that the bacteria count was outside of the acceptable range or ideal count of 20-60 colonies per plate. These USGS data were part of the longer study referenced as Rockwell and Honeywell.
Data Reference: 2007. SWAMP Data for the West Walker River and East Walker River Hydrologic Units
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: The Lahontan Basin Plan's regionwide Water Quality objective for coliform bacteria states: "Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock wastes. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml, nor shall more than 10 percent of all samples collected during any 30-day period exceed 40/100 ml. The log mean shall ideally be based on a minimum of not less than five samples collected as evenly spaced as practicable during any 30-day period. However, a log mean concentration exceeding 20/100 ml for any 30-day period shall indicate violation of this objective even if fewer than five samples were collected."
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: One station, Robinson Creek at Highway 395, was sampled.
Temporal Representation: Robinson Creek was sampled monthly between April 2000 and June 2001.
Environmental Conditions: Robinson Creek originates near the Sierra Nevada Crest. There are several small lakes and streams near its headwaters. Upper and Lower Twin Lakes are onstream glacial lakes that are now managed as reservoirs. Below Lower Twin Lake, Robinson Creek flows about nine miles to Bridgeport REservoir. Near Bridgeport Reservor, the creek flows through wet meadows used for livestock grazing..
QAPP Information: The study was done using USGS quality assurance procedures.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 76458, Indicator Bacteria
Region 6     
Robinson Creek (Twin Lakes to Hwy 395)
 
LOE ID: 129162
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 36
Number of Exceedances: 16
 
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: 16 of the 36 samples exceeded the logmean water quality standard for Coliform, Fecal. This is a 30-day rolling logmean that is calculated daily.
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: Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock wastes. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml. (Lahontan Region Basin Plan)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
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 2010-09-13 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
 
Line of Evidence (LOE) for Decision ID 76458, Indicator Bacteria
Region 6     
Robinson Creek (Twin Lakes to Hwy 395)
 
LOE ID: 129394
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 52
Number of Exceedances: 25
 
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: 25 of the 52 samples exceeded the logmean water quality standard for Coliform, Fecal. This is a 30-day rolling logmean that is calculated daily.
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: Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock wastes. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml. (Lahontan Region Basin Plan)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
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
 
Line of Evidence (LOE) for Decision ID 76458, Indicator Bacteria
Region 6     
Robinson Creek (Twin Lakes to Hwy 395)
 
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)
 
Line of Evidence (LOE) for Decision ID 76458, Indicator Bacteria
Region 6     
Robinson Creek (Twin Lakes to Hwy 395)
 
LOE ID: 129379
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 52
Number of Exceedances: 23
 
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: 23 of the 52 samples exceeded the water quality standard for Coliform, Fecal. The water quality standard 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: Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock wastes. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml, nor shall more than 10 percent of all samples collected during any 30-day period exceed 40/100 ml. (Lahontan Region Basin Plan)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
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
 
Line of Evidence (LOE) for Decision ID 76458, Indicator Bacteria
Region 6     
Robinson Creek (Twin Lakes to Hwy 395)
 
LOE ID: 129452
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 34
Number of Exceedances: 15
 
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: 15 of the 34 samples exceeded the water quality standard for Coliform, Fecal. The water quality standard 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: Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock wastes. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml, nor shall more than 10 percent of all samples collected during any 30-day period exceed 40/100 ml. (Lahontan Region Basin Plan)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
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 2010-09-13 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
 
Line of Evidence (LOE) for Decision ID 76458, Indicator Bacteria
Region 6     
Robinson Creek (Twin Lakes to Hwy 395)
 
LOE ID: 129462
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 22
Number of Exceedances: 9
 
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: 9 of the 22 samples exceeded the water quality standard for Coliform, Fecal. The water quality standard 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: Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock wastes. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml, nor shall more than 10 percent of all samples collected during any 30-day period exceed 40/100 ml. (Lahontan Region Basin Plan)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
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 2012-09-18 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)
 
Line of Evidence (LOE) for Decision ID 76458, Indicator Bacteria
Region 6     
Robinson Creek (Twin Lakes to Hwy 395)
 
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
 
Line of Evidence (LOE) for Decision ID 76458, Indicator Bacteria
Region 6     
Robinson Creek (Twin Lakes to Hwy 395)
 
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
 
Line of Evidence (LOE) for Decision ID 76458, Indicator Bacteria
Region 6     
Robinson Creek (Twin Lakes to Hwy 395)
 
LOE ID: 129428
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 25
Number of Exceedances: 11
 
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: 11 of the 25 samples exceeded the logmean water quality standard for Coliform, Fecal. This is a 30-day rolling logmean that is calculated daily.
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: Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock wastes. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml. (Lahontan Region Basin Plan)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
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 2012-09-18 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)