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

Supporting Information

Regional Board 5 - Central Valley Region

Water Body Name:	Elbow Creek, unnamed tributary below Sheep Meadow (Alpine County)
Water Body ID:	CAR5326001020101020153836
Water Body Type:	River & Stream


DECISION ID	126908	Region 5
Elbow Creek, unnamed tributary below Sheep Meadow (Alpine 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, as applicable, using the E. Coli 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. Additionally, water quality conditions in waterbodies may change as a result of management actions that have been implemented to address bacteria. 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. Five lines of evidence are available based on the new E. coli objective. There are an insufficient number of samples available to apply the binomial distribution table in section 3.2 of the Listing Policy to determine beneficial use support. 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. Based on the readily available data and information, the weight of evidence indicates that there is insufficient 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. There are insufficient samples available to determine listing status using the newly adopted E. coli objective. 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 because applicable water quality standards are not 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 126908, Indicator Bacteria	Region 5
Elbow Creek, unnamed tributary below Sheep Meadow (Alpine County)

LOE ID:

63349

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 of the 3 calculated geomeans exceeded the E. coli evaluation guideline.

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. 1986. 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 Sheep Meadow. WBID: CAR5326001020101020153836

Temporal Representation:

Samples were collected between June 2010 and August 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):

Line of Evidence (LOE) for Decision ID 126908, Indicator Bacteria	Region 5
Elbow Creek, unnamed tributary below Sheep Meadow (Alpine County)

LOE ID:

63350

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 the six samples exceeded the E. coli evaluation guideline.

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 more than 10 percent of total samples during any 30-day period exceed 235/100 ml. (U.S. EPA 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 Sheep Meadow. WBID: CAR5326001020101020153836

Temporal Representation:

Samples were collected between June 2010 and August 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):

Line of Evidence (LOE) for Decision ID 126908, Indicator Bacteria	Region 5
Elbow Creek, unnamed tributary below Sheep Meadow (Alpine County)

LOE ID:

194483

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:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data for Elbow Creek, unnamed tributary below Sheep Meadow (Alpine 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): TEC_SM_L

Temporal Representation:

The samples were collected between the days of 2011-08-31 and 2012-07-18 .

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 126908, Indicator Bacteria	Region 5
Elbow Creek, unnamed tributary below Sheep Meadow (Alpine County)

LOE ID:

194419

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:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data for Elbow Creek, unnamed tributary below Sheep Meadow (Alpine 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): TEC_SM_U

Temporal Representation:

The samples were collected between the days of 2011-08-31 and 2012-07-18 .

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP for Surface Water Ambient Monitoring Project in the Stanislaus National Forest