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

Supporting Information

Regional Board 5 - Central Valley Region

Water Body Name: Cow Creek (Tuolumne County)
Water Body ID: CAR5344105020101028161426
Water Body Type: River & Stream
 
DECISION ID
126898
Region 5     
Cow Creek (Tuolumne County)
 
Pollutant: Indicator Bacteria
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)(2018)
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: The State Water Board’s Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California (the “ISWEBE Plan”) contains two bacteria water quality objectives applicable to the REC-1 beneficial use, which were adopted on August 7, 2018. Because the salinity level of this waterbody is equal to or less than 1 part per thousand 95 percent or more of the time, the E. coli bacteria objective applies Therefore, this waterbody is being considered for placement on the CWA section 303(d) List under section 3.3 of the Listing Policy using the E. coli objective.

A total of twelve lines of evidence of E. coli data were evaluated for this waterbody. Of these lines of evidence, four are based on historic E. coli data collected prior to 2010. Eight are based on recent E.coli data, collected since 2010, and compared to the newer E. coli bacteria water quality objective.

In accordance with section 6.1.5.3 of the Listing Policy, data should be representative of the critical timing that the pollutant is expected to impact the waterbody. Indicator bacteria (total coliform, fecal coliform, E. coli, enterococci) populations may fluctuate substantially on a daily, seasonal, or yearly basis. Lacking constant inputs, they do not persist in the environment for a long period and effects are of relatively short duration. As a result, the historic levels of indicator bacteria in the waterbody may be a poor indicator of current risks to human health, particularly when more recent data are available to sufficiently assess the water quality standard. Unrepresentative data may result in incorrectly placing or not placing a water body segment on the list, which could result in the unnecessary expenditure of public resources or missing a human health problem. The four historic lines of evidence were evaluated pursuant to these considerations and were not used to assess water quality standards attainment because they do not meet the temporal representation requirements of section 6.1.5.3 of the Listing Policy.

The eight recent E. coli lines of evidence were relied upon to assess water quality standards attainment in this waterbody. The data were collected during 2011 - 2017. There are adequate data to determine beneficial use support in accordance with the Listing Policy. The data are representative of existing conditions in the waterbody and represent a range of hydrologic conditions (both wet and dry years).

With respect to the recent lines of evidence, zero of nine geometric means and two of 28 STV for E. coli calculated from 2011 - 2017 exceed the E. coli bacteria objective. For these data, Listing Policy section 3.3 instructs to use the binomial distribution table in section 3.2. Using this exceedance frequency, the number of exceedances is not sufficient to place this waterbody on the list.

No fecal coliform data are used in this assessment because the fecal coliform water quality objective was superseded and is no longer used as the basis of any 303(d) List decision for water contact recreation. Therefore, all lines of evidence available for fecal coliform have been retired.

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.

The data used satisfy the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy.

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: 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.

The data used satisfy the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy.

Pursuant to section 3.11 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.
 
 
Line of Evidence (LOE) for Decision ID 126898, Indicator Bacteria
Region 5     
Cow Creek (Tuolumne County)
 
LOE ID: 194902
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 3
Number of Exceedances: 1
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Cow Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 1 of the 3 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: Water data for the 2020/2022 integrated report in Region 5.
 
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 1 monitoring site(s), station(s): HC20-UCD-Tate
Temporal Representation: The samples were collected between the days of 2016-07-13 and 2016-09-20 .
Environmental Conditions:
QAPP Information: Kenneth W. Tate, Ph.D., CRM. 2011. UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)., Kenneth W. Tate, Ph.D., CRM. 2016. UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP)
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 126898, Indicator Bacteria
Region 5     
Cow Creek (Tuolumne County)
 
LOE ID: 194534
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 6
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Cow Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 0 of the 6 samples exceeded the geomean water quality threshold for E. coli. This is a six week rolling geomean that is calculated weekly.
Data Reference: Water data for the 2020/2022 integrated report in Region 5.
 
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 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 1 monitoring site(s), station(s): CC_BR
Temporal Representation: The samples were collected between the days of 2011-07-26 and 2017-08-23 .
Environmental Conditions:
QAPP Information: Central Sierra Environmental Resource Center. 2010. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center. 2016. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center (CSERC). 2017. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center. 2018. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest.
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
 
Line of Evidence (LOE) for Decision ID 126898, Indicator Bacteria
Region 5     
Cow Creek (Tuolumne County)
 
LOE ID: 194844
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 3
Number of Exceedances: 1
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Cow Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 1 of the 3 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: Water data for the 2020/2022 integrated report in Region 5.
 
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 1 monitoring site(s), station(s): HC1-UCD-Tate
Temporal Representation: The samples were collected between the days of 2016-07-13 and 2016-09-20 .
Environmental Conditions:
QAPP Information: Kenneth W. Tate, Ph.D., CRM. 2011. UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)., Kenneth W. Tate, Ph.D., CRM. 2016. UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP)
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 126898, Indicator Bacteria
Region 5     
Cow Creek (Tuolumne County)
 
LOE ID: 194894
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Cow Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the geomean water quality threshold for E. coli. This is a six week rolling geomean that is calculated weekly.
Data Reference: Water data for the 2020/2022 integrated report in Region 5.
 
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 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 1 monitoring site(s), station(s): HC20-UCD-Tate
Temporal Representation: The samples were collected between the days of 2016-07-13 and 2016-09-20 .
Environmental Conditions:
QAPP Information: Kenneth W. Tate, Ph.D., CRM. 2011. UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)., Kenneth W. Tate, Ph.D., CRM. 2016. UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP)
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 126898, Indicator Bacteria
Region 5     
Cow Creek (Tuolumne County)
 
LOE ID: 194745
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Cow Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the geomean water quality threshold for E. coli. This is a six week rolling geomean that is calculated weekly.
Data Reference: Water data for the 2020/2022 integrated report in Region 5.
 
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 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 1 monitoring site(s), station(s): HC1-UCD-Tate
Temporal Representation: The samples were collected between the days of 2016-07-13 and 2016-09-20 .
Environmental Conditions:
QAPP Information: Kenneth W. Tate, Ph.D., CRM. 2011. UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)., Kenneth W. Tate, Ph.D., CRM. 2016. UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP)
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 126898, Indicator Bacteria
Region 5     
Cow Creek (Tuolumne County)
 
LOE ID: 77248
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 8
Number of Exceedances: 2
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Two of 8 samples exceeded the evaluation guideline for E. coli.
Data Reference: Bacteria Contamination, Violations, and Field Data for Stanislaus, 2009-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River and San Joaquin River Basins)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The U.S. EPA, E. coli objective is 235/100 mL in any single sample (USEPA 1986).
Guideline Reference: Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
 
Spatial Representation: Samples were collected below Bull Run Meadow from a major tributary of Cow Creek (which is within the Herring Creek Range Allotment).
Temporal Representation: Eight water samples were collected between July 9, 2009 and August 13, 2009.
Environmental Conditions: Grazing was first observed in the surrounding meadows on July 9, 2009. The elevation of this sample location is 6,634 ft.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in ¿Surface Water Ambient Monitoring Project in the Santislaus National Forest - Quality Assurance Project Plan ¿
QAPP Information Reference(s): Quality Assurance Project Plan for Stanislaus National Forest by Central Sierra Environmental Resource Center.
 
Line of Evidence (LOE) for Decision ID 126898, Indicator Bacteria
Region 5     
Cow Creek (Tuolumne County)
 
LOE ID: 194761
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Cow Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the geomean water quality threshold for E. coli. This is a six week rolling geomean that is calculated weekly.
Data Reference: Water data for the 2020/2022 integrated report in Region 5.
 
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 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 1 monitoring site(s), station(s): CHC2-UCD-Tate
Temporal Representation: The samples were collected between the days of 2016-07-13 and 2016-09-20 .
Environmental Conditions:
QAPP Information: Kenneth W. Tate, Ph.D., CRM. 2011. UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)., Kenneth W. Tate, Ph.D., CRM. 2016. UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP)
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 126898, Indicator Bacteria
Region 5     
Cow Creek (Tuolumne County)
 
LOE ID: 194933
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Cow Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 0 of the 3 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: Water data for the 2020/2022 integrated report in Region 5.
 
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 1 monitoring site(s), station(s): CHC2-UCD-Tate
Temporal Representation: The samples were collected between the days of 2016-07-13 and 2016-09-20 .
Environmental Conditions:
QAPP Information: Kenneth W. Tate, Ph.D., CRM. 2011. UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)., Kenneth W. Tate, Ph.D., CRM. 2016. UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP).
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment E. coli Monitoring Quality Assurance Project Plan (QAPP)
QAPP Information Reference(s): UC Davis - US Forest Service Grazing Allotment Water Quality Monitoring Quality Assurance Project Plan (QAPP)
 
Line of Evidence (LOE) for Decision ID 126898, Indicator Bacteria
Region 5     
Cow Creek (Tuolumne County)
 
LOE ID: 77279
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Zero of 7 samples exceeded the evaluation guideline for E. coli.
Data Reference: Bacteria Contamination, Violations, and Field Data for Stanislaus, 2009-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River and San Joaquin River Basins)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The U.S. EPA, E. coli objective is 235/100 mL in any single sample (USEPA 1986).
Guideline Reference: Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
 
Spatial Representation: Samples were collected below Bull Run Meadow from a major tributary of Cow Creek (which is within the Herring Creek Range Allotment).
Temporal Representation: The water samples were collected between June 9, 2009 and July 1, 2009.
Environmental Conditions: Grazing was first observed in the surrounding meadows on July 9, 2009. The elevation of this sample location is 6,634 ft.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in ¿Surface Water Ambient Monitoring Project in the Santislaus National Forest - Quality Assurance Project Plan ¿
QAPP Information Reference(s): Quality Assurance Project Plan for Stanislaus National Forest by Central Sierra Environmental Resource Center.
 
Line of Evidence (LOE) for Decision ID 126898, Indicator Bacteria
Region 5     
Cow Creek (Tuolumne County)
 
LOE ID: 95648
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: One geometric mean was calculated from 7 samples. Zero of one calculated geometric means exceeded the evaluation guideline for E. coli.
Data Reference: Bacteria Contamination, Violations, and Field Data for Stanislaus, 2009-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River and San Joaquin River Basins)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The geometric mean of E. coli densities should not exceed 126/100 mL (USEPA 1986).
Guideline Reference: Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
 
Spatial Representation: Samples were collected below Bull Run Meadow from a major tributary of Cow Creek (which is within the Herring Creek Range Allotment).
Temporal Representation: Seven samples were collected between June 9, 2009 and July 1, 2009.
Environmental Conditions: Samples taken before livestock arrival. Grazing was first observed in the surrounding meadows on July 9, 2009. Grazing continued in this allotment until October 1, 2009. The elevation of this sample location is 6,634 ft.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in ¿Surface Water Ambient Monitoring Project in the Santislaus National Forest - Quality Assurance Project Plan ¿
QAPP Information Reference(s): Quality Assurance Project Plan for Stanislaus National Forest by Central Sierra Environmental Resource Center.
 
Line of Evidence (LOE) for Decision ID 126898, Indicator Bacteria
Region 5     
Cow Creek (Tuolumne County)
 
LOE ID: 77241
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 3
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Three geometric means were calculated from 8 samples. Geometric means were calculated from 5, 5, and 4 samples respectively. Zero of three calculated geometric means exceeded the evaluation guideline for E. coli.
Data Reference: Bacteria Contamination, Violations, and Field Data for Stanislaus, 2009-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River and San Joaquin River Basins)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The geometric mean of E. coli densities should not exceed 126/100 mL (USEPA 1986).
Guideline Reference: Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
 
Spatial Representation: Samples were collected below Bull Run Meadow from a major tributary of Cow Creek (which is within the Herring Creek Range Allotment).
Temporal Representation: Eight water samples were collected between July 9, 2009 and August 13, 2009.
Environmental Conditions: Samples were collected after livestock Grazing was first observed in the surrounding meadows on July 9, 2009. Grazing continued in this allotment until October 1, 2009. The elevation of this sample location is 6,634 ft.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in ¿Surface Water Ambient Monitoring Project in the Santislaus National Forest - Quality Assurance Project Plan ¿
QAPP Information Reference(s): Quality Assurance Project Plan for Stanislaus National Forest by Central Sierra Environmental Resource Center.
 
Line of Evidence (LOE) for Decision ID 126898, Indicator Bacteria
Region 5     
Cow Creek (Tuolumne County)
 
LOE ID: 194519
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 19
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Cow Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 0 of the 19 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: Water data for the 2020/2022 integrated report in Region 5.
 
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 1 monitoring site(s), station(s): CC_BR
Temporal Representation: The samples were collected between the days of 2011-07-26 and 2017-08-23 .
Environmental Conditions:
QAPP Information: Central Sierra Environmental Resource Center. 2010. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center. 2016. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center (CSERC). 2017. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest., Central Sierra Environmental Resource Center. 2018. QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest.
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest
QAPP Information Reference(s): QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest