Final California 2018 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	74069	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)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Eight lines of evidence are available in the administrative record to assess this pollutant. Two of 15 samples exceed the single samples evaluation guideline for Escherichia coli (E. coli) and zero of 4 calculated geomeans exceed the evaluation guideline for E. coli. Two of 15 samples exceed the water quality objective for fecal coliform and zero of four calculated geomeans exceed the water quality objective for fecal coliform. 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. 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. Two of 15 samples exceed the single samples evaluation guideline for Escherichia coli (E. coli) and zero of 4 calculated geomeans exceed the evaluation guideline for E. coli. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 26 samples is needed to determine if a beneficial use is fully supported using table 3.2. 4. Two of 15 samples exceed the water quality objective for fecal coliform and zero of four calculated geomeans exceed the water quality objective for fecal coliform.This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 26 samples is needed to determine if a beneficial use is fully supported using table 3.2. 5. 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:

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 74069, Indicator Bacteria	Region 5
Cow Creek (Tuolumne County)

LOE ID:

77277

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

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 the three calculated geometric means exceeded the water quality objective for fecal coliform.

Data Reference:

Bacteria Contamination, Violations, and Field Data for Stanislaus, 2009-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

In waters designated for contact recreation (REC-1), the fecal coliform concentration based on a minimum of not less than five samples for any 30-day period shall not exceed a geometric mean of 200/100 ml, nor shall more than ten percent of the total number of samples taken during any 30-day period exceed 400/100 ml.

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:

Guideline Reference:

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 74069, Indicator Bacteria	Region 5
Cow Creek (Tuolumne County)

LOE ID:

77278

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Zero of 7 water samples exceeded the water quality objective for fecal coliform.

Data Reference:

Bacteria Contamination, Violations, and Field Data for Stanislaus, 2009-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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:

Guideline Reference:

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 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 Stanislaus 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 74069, Indicator Bacteria	Region 5
Cow Creek (Tuolumne County)

LOE ID:

77275

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

One of 8 total samples exceeded 400/100 ml.

Data Reference:

Bacteria Contamination, Violations, and Field Data for Stanislaus, 2009-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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:

Guideline Reference:

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:

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 74069, 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:

Number of Exceedances:

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:

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 74069, 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:

Number of Exceedances:

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:

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:

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 74069, 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:

Number of Exceedances:

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:

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:

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 74069, 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:

Number of Exceedances:

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:

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:

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 74069, Indicator Bacteria	Region 5
Cow Creek (Tuolumne County)

LOE ID:

95649

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Geomentric means were calculated for samples taken before livestock arrival. One geomentric means were calculated from 7 samples. Zero of one calculated geometric means exceededthe water quality objective for fecal coliform.

Data Reference:

Bacteria Contamination, Violations, and Field Data for Stanislaus, 2009-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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:

Guideline Reference:

Spatial Representation:

Samples were collected below Bull Run Meadow from a major tributary of Cow Creek (which is within the Herring Creek Range Allotment). The elevation of this sample location is 6,634 ft.

Temporal Representation:

Grazing was first observed in the surrounding meadows on July 9, 2009. Seven samples were collected prior to livestock arrival between June 9, 2009 and July 1, 2009. Grazing continued in this allotment until October 1, 2009.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for Stanislaus National Forest by Central Sierra Environmental Resource Center.