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

Supporting Information

Regional Board 5 - Central Valley Region

Water Body Name:	Bourland Creek (Tuolumne County)
Water Body ID:	CAR5364002320101020160322
Water Body Type:	River & Stream


DECISION ID	127121	Region 5
Bourland 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:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. No new fecal coliform data are used in this assessment because the fecal coliform water quality objective was superseded and is no longer used as the basis of any 303(d) List decision for water contact recreation.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.

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 127121, Indicator Bacteria	Region 5
Bourland Creek (Tuolumne County)

LOE ID:

60671

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 3 geomeans exceeded the E. coli objective.

Data Reference:

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

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 objective for E. coli in freshwater is 126 MPN/100mL. 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 from Bourland Creek. CAR5364002320101020160322

Temporal Representation:

Samples were collected form July to August of 2009 and June to August of 2010.

Environmental Conditions:

Samples were collected from a natural meadow that was not grazed.

QAPP Information:

Samples were collected under the 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.

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 127121, Indicator Bacteria	Region 5
Bourland Creek (Tuolumne County)

LOE ID:

60670

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 11 samples exceeded the E. coli objective.

Data Reference:

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

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:

Single sample maximum allowable density for E. coli in freshwater is 235 MPN/100mL. 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 from Bourland Creek.

Temporal Representation:

Samples were collected form July to August of 2009 and June to August of 2010. CAR5364002320101020160322

Environmental Conditions:

Samples were collected from a natural meadow that was not grazed.

QAPP Information:

Samples were collected under the Surface Water Ambient Monitoring Project in the Stanislaus National Forest Quality Assurance Project Plan. QA9

QAPP Information Reference(s):

Quality Assurance Project Plan for Stanislaus National Forest.

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 127121, Indicator Bacteria	Region 5
Bourland Creek (Tuolumne County)

LOE ID:

194434

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 Bourland Creek (Tuolumne County) to determine beneficial use support and the results are as follows: 0 of the 5 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): BouC_BoM_2

Temporal Representation:

The samples were collected between the days of 2017-06-23 and 2018-08-15 .

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 127121, Indicator Bacteria	Region 5
Bourland Creek (Tuolumne County)

LOE ID:

194518

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 Bourland 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:

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): BOUC_BOM

Temporal Representation:

The samples were collected between the days of 2012-07-31 and 2013-08-13 .

Environmental Conditions:

QAPP Information:

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 127121, Indicator Bacteria	Region 5
Bourland Creek (Tuolumne County)

LOE ID:

77242

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 geometric means were calculated from 6 samples. Each geomean was calculated from 5 samples. Zero of 2 calculcated geometric means exceeded the evaluation guideline for E. coli

Data Reference:

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

SWAMP Data:

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 Bourland Meadow from Bourland Creek.

Temporal Representation:

Six water quality samples were taken between July 14, 2009 and August 28, 2009. Flows at the original sample site below Bourland Meadow had receded by July 24, 2009; on that date the sample site was moved a short distance downstream to a new location on Bourland Creek that had adequate flows for sampling.

Environmental Conditions:

Bourland Meadow lies within a designated research natural area where grazing is prohibited. This site was not grazed and served as the control site. The elevation of this sample location is 7,299 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.