Draft California 2018 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 6 - Lahontan Region

Water Body Name:	Tallac Creek (below Hwy 89)
Water Body ID:	CAR6341004120020116164425
Water Body Type:	River & Stream


DECISION ID	80024	Region 6
Tallac Creek (below Hwy 89)

Pollutant:	Indicator Bacteria
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2016)
Revision Status	Revised
Sources:	Source Unknown
Expected TMDL Completion Date:	2031
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Staff 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. Five lines of evidence, two which assess E. coli data for the REC-1 beneficial use, two which assess fecal coliform data for the MUN beneficial use and one which is a placeholder LOE for pathogens written prior to 2006 (and thus the data are not readily available) are available in the administrative record to assess this pollutant. The placeholder LOE shows that the waterbody was listed in past cycles but the data is not readily available. 2 of 80 samples exceed the water quality objective for E. coli data assessed against the REC-1 beneficial use; 18 of 94 fecal coliform geometric mean samples and 9 of 27 fecal coliform statistical threshold value samples exceed the objective for MUN; an unknown number so samples exceed the water quality objective for pathogens as these data were assessed during a previous listing cycle and these data are currently unavailable. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of keeping 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. 18 of 94 fecal coliform geometric mean samples and 9 of 27 fecal coliform statistical threshold value samples exceed the objective for MUN and this exceeds the allowable exceedance frequency stipulated in table 4.2 of the listing policy. 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 Staff Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

Line of Evidence (LOE) for Decision ID 80024, Indicator Bacteria	Region 6
Tallac Creek (below Hwy 89)

LOE ID:

99764

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 RWB6_BACT_Monitoring data for Tallac Creek (below Hwy 89) to determine beneficial use support and the results are as follows: 2 of the 28 samples exceeded the Statistical Threshold Value (STV) water quality standard for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for Regional Water Board 6 Bacteria Monitoring.

SWAMP Data:

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): 634TALB01

Temporal Representation:

The samples were collected between the days of 2010-08-31 and 2015-06-29 .

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

Line of Evidence (LOE) for Decision ID 80024, Indicator Bacteria	Region 6
Tallac Creek (below Hwy 89)

LOE ID:

129368

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB6_BACT_Monitoring data for Tallac Creek (below Hwy 89) to determine beneficial use support and the results are as follows: 9 of the 28 samples exceeded the water quality standard for Coliform, Fecal. The water quality standard is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for Regional Water Board 6 Bacteria Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock wastes. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml, nor shall more than 10 percent of all samples collected during any 30-day period exceed 40/100 ml. (Lahontan Region Basin Plan)

Objective/Criterion Reference:

Water Quality Control Plan for the Lahontan Region (as amended)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 634TALB01

Temporal Representation:

The samples were collected between the days of 2010-08-31 and 2015-06-29 .

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

Line of Evidence (LOE) for Decision ID 80024, Indicator Bacteria	Region 6
Tallac Creek (below Hwy 89)

LOE ID:

129262

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB6_BACT_Monitoring data for Tallac Creek (below Hwy 89) to determine beneficial use support and the results are as follows: 18 of the 94 samples exceeded the logmean water quality standard for Coliform, Fecal. This is a 30-day rolling logmean that is calculated daily.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for Regional Water Board 6 Bacteria Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Lahontan Region (as amended)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 634TALB01

Temporal Representation:

The samples were collected between the days of 2010-08-31 and 2015-06-29 .

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

Line of Evidence (LOE) for Decision ID 80024, Indicator Bacteria	Region 6
Tallac Creek (below Hwy 89)

LOE ID:

4642

Pollutant:

Pathogens

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.

Data Reference:

Placeholder reference pre-2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Unspecified

Objective/Criterion Reference:

Placeholder reference pre-2006 303(d)

Evaluation Guideline:

Unspecified

Guideline Reference:

Placeholder reference pre-2006 303(d)

Spatial Representation:

Unspecified

Temporal Representation:

Unspecified

Environmental Conditions:

Unspecified

QAPP Information:

Unspecified

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 80024, Indicator Bacteria	Region 6
Tallac Creek (below Hwy 89)

LOE ID:

99672

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 RWB6_BACT_Monitoring data for Tallac Creek (below Hwy 89) to determine beneficial use support and the results are as follows: 0 of the 52 samples exceeded the geomean water quality standard for E. coli. This is a six week rolling geomean that is calculated weekly.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for Regional Water Board 6 Bacteria Monitoring.

SWAMP Data:

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): 634TALB01

Temporal Representation:

The samples were collected between the days of 2010-08-31 and 2015-06-29 .

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program