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

Supporting Information

Regional Board 5 - Central Valley Region

Water Body Name:	Cottonwood Creek, unnamed tributary at Cottonwood Meadow (Tuolumne County)
Water Body ID:	CAR5365107020101020130014
Water Body Type:	River & Stream


DECISION ID	85963	Region 5
Cottonwood Creek, unnamed tributary at Cottonwood Meadow (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 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. Six lines of evidence are available in the administrative record to assess this pollutant. Zero of 10 samples exceed the evaluation guideline for Escherichia coli (E. coli), zero of 10 samples exceed the water quality objective for fecal coliform, and zero of 10 samples exceed the evaluation guideline for total 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 section 303(d) list in the Water Quality Limited Segments category. 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. Zero of 10 samples exceed the evaluation guideline for E. coli, zero of 10 samples exceed the water quality objective for fecal coliform, and zero of 10 samples exceed the evaluation guideline for total 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. 4. 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 85963, Indicator Bacteria	Region 5
Cottonwood Creek, unnamed tributary at Cottonwood Meadow (Tuolumne County)

LOE ID:

61991

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 the three geomeans exceeded the E. coli objective.

Data Reference:

Data for Fecal Col, E.coli, and Observations in Region 5 for Various Water Bodies, 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 for E. coli shall not exceed 126/100 ml. USEPA Ambient Water Quality Criteria for Bacteria - 1986.

Guideline Reference:

Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002

Spatial Representation:

The samples were collected at Cottonwood Meadow. WBID: CAR5365107020101020130014

Temporal Representation:

Samples were collected between May 2010 and July 2010.

Environmental Conditions:

QAPP Information:

Samples were collected under the Bacteria Contamination of Surface Waters Due to Livestock Grazing in the Stanislaus National Forest, California (Second Year of Study).

QAPP Information Reference(s):

Quality Assurance Project Plan for Stanislaus National Forest.

Line of Evidence (LOE) for Decision ID 85963, Indicator Bacteria	Region 5
Cottonwood Creek, unnamed tributary at Cottonwood Meadow (Tuolumne County)

LOE ID:

61994

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 the seven samples exceeded the fecal coliform objective.

Data Reference:

Data for Fecal Col, E.coli, and Observations in Region 5 for Various Water Bodies, 2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The fecal coliform concentration shall not exceed 400/100 ml. Water Quality Control Plan for Central Valley Regional Water Quality Control Board, 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:

Guideline Reference:

Spatial Representation:

The samples were collected at Cottonwood Meadow. WBID: CAR5365107020101020130014

Temporal Representation:

Samples were collected between May 2010 and July 2010.

Environmental Conditions:

QAPP Information:

Samples were collected under the Bacteria Contamination of Surface Waters Due to Livestock Grazing in the Stanislaus National Forest, California (Second Year of Study).

QAPP Information Reference(s):

Quality Assurance Project Plan for Stanislaus National Forest.

Line of Evidence (LOE) for Decision ID 85963, Indicator Bacteria	Region 5
Cottonwood Creek, unnamed tributary at Cottonwood Meadow (Tuolumne County)

LOE ID:

61993

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 the 3 geomeans exceeded the fecal coliform objective.

Data Reference:

Data for Fecal Col, E.coli, and Observations in Region 5 for Various Water Bodies, 2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Geometric mean: The fecal coliform concentration shall not exceed 200/100 ml. Water Quality Control Plan for Central Valley Regional Water Quality Control Board.

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:

The samples were collected at Cottonwood Meadow. WBID: CAR5365107020101020130014

Temporal Representation:

Samples were collected between May 2010 to July 2010.

Environmental Conditions:

QAPP Information:

Samples were collected under the Bacteria Contamination of Surface Waters Due to Livestock Grazing in the Stanislaus National Forest, California (Second Year of Study).

QAPP Information Reference(s):

Quality Assurance Project Plan for Stanislaus National Forest.

Line of Evidence (LOE) for Decision ID 85963, Indicator Bacteria	Region 5
Cottonwood Creek, unnamed tributary at Cottonwood Meadow (Tuolumne County)

LOE ID:

61992

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 the seven samples exceeded the e. coli objective.

Data Reference:

Data for Fecal Col, E.coli, and Observations in Region 5 for Various Water Bodies, 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 e coli concentration shall not exceed 235/100 ml. USEPA Ambient Water Quality Criteria for Bacteria - 1986.

Guideline Reference:

Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002

Spatial Representation:

The samples were collected at Cottonwood Meadow. WBID: CAR5365107020101020130014

Temporal Representation:

Samples were collected between May 2010 and July 2010.

Environmental Conditions:

QAPP Information:

Samples were collected under the Bacteria Contamination of Surface Waters Due to Livestock Grazing in the Stanislaus National Forest, California (Second Year of Study).

QAPP Information Reference(s):

Quality Assurance Project Plan for Stanislaus National Forest.