Draft California 2024 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 2 - San Francisco Bay Region

Water Body Name:	Tomales Bay
Water Body ID:	CAB2011403319980929125721
Water Body Type:	Bay & Harbor


DECISION ID	151202	Region 2
Tomales Bay

Pollutant:	Nutrients
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)(2018)
Revision Status	Revised
Sources:	A Source Unknown
Expected TMDL Completion Date:	2037
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed.

Regional Board Decision Recommendation:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current. The decision has not changed.

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 151202, Nutrients	Region 2
Tomales Bay

LOE ID:

3712

Pollutant:

Nutrients

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Estuarine Habitat

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:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Unspecified

Temporal Representation:

Unspecified

Environmental Conditions:

Unspecified

QAPP Information:

Unspecified

QAPP Information Reference(s):


DECISION ID	151397	Region 2
Tomales Bay

Pollutant:	Sediment
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	A Source Unknown
Expected TMDL Completion Date:	2037
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This is a carryover decision. The original decision was retired because the pollutant name was changed from "Sedimentation/siltation" to "sediment" 303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed.

Regional Board Decision Recommendation:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 151397, Sediment	Region 2
Tomales Bay

LOE ID:

3713

Pollutant:

Sedimentation/Siltation

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Estuarine Habitat

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:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Unspecified

Temporal Representation:

Unspecified

Environmental Conditions:

Unspecified

QAPP Information:

Unspecified

QAPP Information Reference(s):


DECISION ID	149036	Region 2
Tomales Bay

Pollutant:	Indicator Bacteria
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	Agriculture-animal \| Onsite Wastewater Systems (Septic Tanks)
TMDL Name:	Tomales Bay Pathogens
TMDL Project Code:	10
Date TMDL Approved by USEPA:	02/08/2007
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal on the CWA section 303(d) List under sections 2.2 and section 4.2 of the Listing Policy. Under section 4.2 of the Policy, a minimum of one line of evidence is needed to assess listing status. Five lines of evidence are available in the administrative record to assess this pollutant. Four of forty-five samples exceeded the 90th percentile fecal coliform objective from the Basin Plan to protect the shellfish beneficial use. During the period July 2017- June 2018, there were 94 rainfall closure days of the shellfish harvesting areas in Tomales Bay. There were 150 such closure days during July 2018- June 2019 and 98 such closure days from July 2019 through June 2020. These closure days occur when the concentration of the illness causing microbe Vibrio parahaemolyticus reaches 10,000 MPN/g or greater. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. There is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard. 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. Four of forty-five samples exceeded the 90th percentile fecal coliform Basin plan objective to protect shellfish harvesting and these DO NOT exceed the allowable frequency listed in Table 4-2 of the Listing Policy. 4. There are still numerous days in which high number of closure days in shellfish growing areas of Tomales Bay as stated above. These closure days suggest that the shellfish beneficial use is not being protected. 4. The TMDL Pathogens TMDL was approved by USEPA on 2/8/2007. 5. Pursuant to section 4.11 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 removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 149036, Indicator Bacteria	Region 2
Tomales Bay

LOE ID:

300279

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Mean

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB2 Monitoring data for Tomales Bay to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the 30-day mean water quality threshold for Coliform, Fecal.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.1 Bacteria: Table 3-1 provides a summary of the bacterial water quality objectives and identifies the sources of those objectives. The fecal coliform objective for non-contact recreation is a 30-day mean less than 2000 MPN/100 ML.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 201TMB600 (Inner Tomales Bay Site Tomales Bay Oyster sampled).

Temporal Representation:

The samples were collected between the days of 2019-08-13 and 2020-10-06 .

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 149036, Indicator Bacteria	Region 2
Tomales Bay

LOE ID:

300420

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

90th percentile

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB2 Monitoring data for Tomales Bay to determine beneficial use support and the results are as follows: 0 of the 15 samples exceeded the water quality threshold for Coliform, Fecal. The water quality threshold is based on a 30-day 90% percentile.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 201TMB400 (Middle Tomales Bay Site Hog Island Oyster Co sampled).

Temporal Representation:

The samples were collected between the days of 2019-08-06 and 2020-10-06 .

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 149036, Indicator Bacteria	Region 2
Tomales Bay

LOE ID:

300533

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

90th percentile

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB2 Monitoring data for Tomales Bay to determine beneficial use support and the results are as follows: 0 of the 11 samples exceeded the water quality threshold for Coliform, Fecal. The water quality threshold is based on a 30-day 90% percentile.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.1 Bacteria: Table 3-1 provides a summary of the bacterial water quality objectives and identifies the sources of those objectives. The fecal coliform objective for shellfish harvesting is a 30-day 90th percentile less than 43 MPN/100 ML.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 201TMB600 (Inner Tomales Bay Site Tomales Bay Oyster sampled).

Temporal Representation:

The samples were collected between the days of 2019-08-13 and 2020-10-06 .

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 149036, Indicator Bacteria	Region 2
Tomales Bay

LOE ID:

300549

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Mean

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB2 Monitoring data for Tomales Bay to determine beneficial use support and the results are as follows: 0 of the 2 samples exceeded the 30-day mean water quality threshold for Coliform, Fecal.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 201TMB400 (Middle Tomales Bay Site Hog Island Oyster Co sampled).

Temporal Representation:

The samples were collected between the days of 2019-08-06 and 2020-10-06 .

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 149036, Indicator Bacteria	Region 2
Tomales Bay

LOE ID:

300239

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Median

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB2 Monitoring data for Tomales Bay to determine beneficial use support and the results are as follows: 0 of the 2 samples exceeded the water quality threshold for Coliform, Fecal. The water quality threshold for shellfish is based on the median concentration at each station, and is calculated as a 30-day median.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.1 Bacteria: Table 3-1 provides a summary of the bacterial water quality objectives and identifies the sources of those objectives. The fecal coliform objective for shellfish harvesting is a 30-day median less than 14 MPN/100 ML.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 201TMB200 (Outer Tomales Bay Hog Island Oyster Co sampled).

Temporal Representation:

The samples were collected between the days of 2019-08-06 and 2020-10-06 .

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 149036, Indicator Bacteria	Region 2
Tomales Bay

LOE ID:

300358

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

90th percentile

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.1 Bacteria: Table 3-1 provides a summary of the bacterial water quality objectives and identifies the sources of those objectives. The fecal coliform objective for shellfish harvesting is a 30-day 90th percentile less than 43 MPN/100 ML.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 201TMB400 (Middle Tomales Bay Site Hog Island Oyster Co sampled).

Temporal Representation:

The samples were collected between the days of 2019-08-06 and 2020-10-06 .

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 149036, Indicator Bacteria	Region 2
Tomales Bay

LOE ID:

300458

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Mean

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 201TMB200 (Outer Tomales Bay Hog Island Oyster Co sampled).

Temporal Representation:

The samples were collected between the days of 2019-08-06 and 2020-10-06 .

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 149036, Indicator Bacteria	Region 2
Tomales Bay

LOE ID:

300300

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

90th percentile

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 201TMB600 (Inner Tomales Bay Site Tomales Bay Oyster sampled).

Temporal Representation:

The samples were collected between the days of 2019-08-13 and 2020-10-06 .

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 149036, Indicator Bacteria	Region 2
Tomales Bay

LOE ID:

300378

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Median

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB2 Monitoring data for Tomales Bay to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the water quality threshold for Coliform, Fecal. The water quality threshold for shellfish is based on the median concentration at each station, and is calculated as a 30-day median.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.1 Bacteria: Table 3-1 provides a summary of the bacterial water quality objectives and identifies the sources of those objectives. The fecal coliform objective for shellfish harvesting is a 30-day median less than 14 MPN/100 ML.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 201TMB600 (Inner Tomales Bay Site Tomales Bay Oyster sampled).

Temporal Representation:

The samples were collected between the days of 2019-08-13 and 2020-10-06 .

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 149036, Indicator Bacteria	Region 2
Tomales Bay

LOE ID:

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 2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QA Info Missing

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 149036, Indicator Bacteria	Region 2
Tomales Bay

LOE ID:

300388

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

90th percentile

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB2 Monitoring data for Tomales Bay to determine beneficial use support and the results are as follows: 4 of the 4 samples exceeded the water quality threshold for Coliform, Fecal. The water quality threshold is based on a 30-day 90% percentile.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.1 Bacteria: Table 3-1 provides a summary of the bacterial water quality objectives and identifies the sources of those objectives. The fecal coliform objective for shellfish harvesting is a 30-day 90th percentile less than 43 MPN/100 ML.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 201WTG010 (White Gulch bear Pierce Point just us of Tomales Bay TBWC sampled.).

Temporal Representation:

The samples were collected between the days of 2019-12-03 and 2020-03-03 .

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 149036, Indicator Bacteria	Region 2
Tomales Bay

LOE ID:

300318

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

90th percentile

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.1 Bacteria: Table 3-1 provides a summary of the bacterial water quality objectives and identifies the sources of those objectives. The fecal coliform objective for shellfish harvesting is a 30-day 90th percentile less than 43 MPN/100 ML.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 201TMB200 (Outer Tomales Bay Hog Island Oyster Co sampled).

Temporal Representation:

The samples were collected between the days of 2019-08-06 and 2020-10-06 .

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 149036, Indicator Bacteria	Region 2
Tomales Bay

LOE ID:

300441

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

90th percentile

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 201TMB200 (Outer Tomales Bay Hog Island Oyster Co sampled).

Temporal Representation:

The samples were collected between the days of 2019-08-06 and 2020-10-06 .

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 149036, Indicator Bacteria	Region 2
Tomales Bay

LOE ID:

300537

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

90th percentile

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB2 Monitoring data for Tomales Bay to determine beneficial use support and the results are as follows: 0 of the 4 samples exceeded the water quality threshold for Coliform, Fecal. The water quality threshold is based on a 30-day 90% percentile.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 201WTG010 (White Gulch bear Pierce Point just us of Tomales Bay TBWC sampled.).

Temporal Representation:

The samples were collected between the days of 2019-12-03 and 2020-03-03 .

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 149036, Indicator Bacteria	Region 2
Tomales Bay

LOE ID:

300393

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Median

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.1 Bacteria: Table 3-1 provides a summary of the bacterial water quality objectives and identifies the sources of those objectives. The fecal coliform objective for shellfish harvesting is a 30-day median less than 14 MPN/100 ML.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 201TMB400 (Middle Tomales Bay Site Hog Island Oyster Co sampled).

Temporal Representation:

The samples were collected between the days of 2019-08-06 and 2020-10-06 .

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.


DECISION ID	152861	Region 2
Tomales Bay

Pollutant:	Mercury
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)(2018)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Name:	Tomales Bay Mercury
TMDL Project Code:	68
Date TMDL Approved by USEPA:	07/03/2012
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.5 and 4.11 of the Listing Policy. Under section 4.5 a single line of evidence is necessary to assess listing status. Under section 4.11 when all other delisting factors do not result in the delisting of a water segment but information indicates attainment of standards, a water segment shall be evaluated to determine whether the weight of evidence demonstrates that water quality standard is attained. If the weight of evidence indicates attainment, the water segment shall be removed from the CWA section 303(d) List. Twenty-five lines of evidence are available in the administrative record to assess the pollutant. LOE 4 is replaced with LOE 307494. LOE 307494 is a reassessment of the same data following the statewide mercury objectives adopted in 2017. COMM beneficial use (sport fish objective): LOE 307494: 0 of 2 samples exceed the mercury objective and consist of 47 trophic level 3 fish. MAR beneficial use (prey fish objective): Tissue - LOE 269199: 1 of 1 samples exceed the mercury objective and consist of 8 trophic level 3 and 4 fish. Tissue - LOE 307546: 1 of 1 samples exceed the mercury objective and consist of 60 trophic level 3 and 4 fish. MAR beneficial use (sport fish objective): Tissue - LOE 307485: 0 of 2 samples exceed the mercury objective and consist of 47 trophic level 3 fish. MAR beneficial use (sediment): Sediment - 0 of 17 sediment samples exceed the mercury guideline. WILD beneficial use (prey fish objective): LOE 269157: 1 of 1 samples exceed the mercury objective and consist of 8 trophic level 3 and 4 fish. LOE 307557: 1 of 1 samples exceed the mercury objective and consist of 60 trophic level 3 and 4 fish. WILD beneficial use (sport fish objective): LOE 307470: 0 of 2 samples exceed the mercury objective and consist of 47 trophic level 3 fish. SHELL beneficial use: 0 of 1 shellfish tissue sample exceed the mercury guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. There is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard. 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. Tissue samples were compared with the prey fish objective and 2 of 2 samples exceed for WILD beneficial use and 2 of 2 samples exceed for MAR beneficial use. Samples may consist of a mix of trophic levels and are from a minimum of 2 annual averages and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. The Tomales Bay Mercury TMDL was approved by USEPA on 7/3/2012. 5. Pursuant to section 4.11 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 removed from the section 303(d) list because applicable water quality standards for the pollutant are 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 152861, Mercury	Region 2
Tomales Bay

LOE ID:

307470

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TSMP 1998-2002 data for Tomales Bay to determine beneficial use support and the results are as follows: 0 of the 2 samples exceeded the water quality threshold for Mercury. This LOE contains data only for trophic level 3 fish. The concentration of Mercury in fish collected within the same calendar year, for the same trophic level were averaged into a single sample for comparison with the objective. A total of 47 fish were aggregated into 2 annual averages, which consisted of 3 fish species (3 composite(s) of Redtail Surfperch each composed of 3 fish per composite, 7 composite(s) of Jacksmelt each composed of 5 fish per composite, 1 composite(s) of Bat Ray each composed of 3 fish per composite).

Data Reference:

Chemical Concentrations in Fish Tissues from Selected Reservoirs and Coastal Areas in the San Francisco Bay Region. Final Report.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The Statewide Sport Fish Water Quality Objective for the protection of Wildlife Habitat comes from the Statewide Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California, and is 0.2 mg/Kg wet weight skinless fillet samples of trophic level 3, or trophic level 4 fish (whichever is highest in the water body) over a one year averaging period. If trophic level 3 fish are used in the assessment then the Prey Fish Water Quality Objective must also be used to determine that the Sport Fish Objective is being met. Trophic levels of applicable fish are defined in, but not limited to those in Attachment C of the Final Regulatory Language document (Appendix A) of State Water Resources Control Board Resolution No. 2017-0027.

Guideline 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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): Outer Bay, Mid Bay (Tomales Bay).

Temporal Representation:

Data for this line of evidence were collected between 1998-08-11 and 1999-05-06. When composited fish were collected over multiple days, the first day of fish collection was used as the sample date in the LOE, both for LOE writing, and for averaging period purposes.

Environmental Conditions:

QAPP Information:

Environmental Chemistry Quality Assurance and Data Report for the Toxic Substances Monitoring Program. Department of Fish and Game.

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

274419

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB2 Monitoring data for Tomales Bay to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Mercury .

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The evaluation guideline for mercury is 2.1 ug/g (PTI Environmental Services, 1991).

Guideline Reference:

Pollutants of concern in Puget Sound. EPA 910/9-91-003. Seattle, WA: U.S. Environmental Protection Agency

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 201WLKD05 (Walker Creek Delta HP N Flat A).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-09-25 to 2018-09-25

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

274561

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The evaluation guideline for mercury is 2.1 ug/g (PTI Environmental Services, 1991).

Guideline Reference:

Pollutants of concern in Puget Sound. EPA 910/9-91-003. Seattle, WA: U.S. Environmental Protection Agency

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 201WLKD03 (Walker Creek Delta HP S Flat A).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-09-25 to 2018-09-25

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

274448

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The evaluation guideline for mercury is 2.1 ug/g (PTI Environmental Services, 1991).

Guideline Reference:

Pollutants of concern in Puget Sound. EPA 910/9-91-003. Seattle, WA: U.S. Environmental Protection Agency

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 201WLKD09 (Walker Creek Delta Preston A).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-09-25 to 2018-09-25

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

274330

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The evaluation guideline for mercury is 2.1 ug/g (PTI Environmental Services, 1991).

Guideline Reference:

Pollutants of concern in Puget Sound. EPA 910/9-91-003. Seattle, WA: U.S. Environmental Protection Agency

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 201WLKD20 (Walker Creek Delta Roar Pickle B).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-09-25 to 2018-09-25

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

269199

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB2 Monitoring data for Tomales Bay to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the water quality threshold for Mercury. All fish collected between February and July of the same calendar year with a reported length of 50-150 mm were averaged into a single sample, independent of species of trophic level, for comparison with the objective. This LOE consists of a total of 8 fish, which were aggregated into 1 annual averages, consisting of 3 fish species (1 composite(s) of Longjaw Mudsucker each composed of 4 fish per composite, 1 composite(s) of Pacific Staghorn Sculpin each composed of 1 fish per composite, 1 composite(s) of Pacific Staghorn Sculpin each composed of 3 fish per composite). Of these annual averages, 1 average(s), (Year(s): 2019) exceeded the objective.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The Statewide Prey Fish Water Quality Objective for the protection of Marine Habitat comes from the Statewide Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California, and is 0.05 mg/Kg wet weight whole fish samples of any fish species between 50 to 150 mm in total length collected between February 1 and July 31. (SWRCB Resolution No. 2017-0027)

Guideline 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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 201WLKD19 (Walker Creek Delta Roar Pickle A).

Temporal Representation:

Data for this line of evidence were collected between 2019-07-02 and 2019-07-16. When composited fish were collected over multiple days, the first day of fish collection was used as the sample date in the LOE, both for LOE writing, and for averaging period purposes.

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

307557

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed TSMP 1998-2002 data for Tomales Bay to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the water quality threshold for Mercury. All fish collected between February and July of the same calendar year with a reported length of 50-150 mm were averaged into a single sample, independent of species of trophic level, for comparison with the objective. This LOE consists of a total of 60 fish, which were aggregated into 1 annual averages, consisting of 1 fish species (3 composite(s) of Shiner Surfperch each composed of 20 fish per composite). Of these annual averages, 1 average(s), (Year(s): 1999) exceeded the objective.

Data Reference:

Chemical Concentrations in Fish Tissues from Selected Reservoirs and Coastal Areas in the San Francisco Bay Region. Final Report.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The Statewide Prey Fish Water Quality Objective for the protection of Wildlife Habitat comes from the Statewide Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California, and is 0.05 mg/Kg wet weight whole fish samples of any fish species between 50 to 150 mm in total length collected between February 1 and July 31. (SWRCB Resolution No. 2017-0027)

Guideline 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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): Outer Bay, Mid Bay (Tomales Bay).

Temporal Representation:

Data for this line of evidence were collected between 1999-05-04 and 1999-05-04. When composited fish were collected over multiple days, the first day of fish collection was used as the sample date in the LOE, both for LOE writing, and for averaging period purposes.

Environmental Conditions:

QAPP Information:

Environmental Chemistry Quality Assurance and Data Report for the Toxic Substances Monitoring Program. Department of Fish and Game.

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

307546

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Chemical Concentrations in Fish Tissues from Selected Reservoirs and Coastal Areas in the San Francisco Bay Region. Final Report.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

Guideline 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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): Outer Bay, Mid Bay (Tomales Bay).

Temporal Representation:

Environmental Conditions:

QAPP Information:

Environmental Chemistry Quality Assurance and Data Report for the Toxic Substances Monitoring Program. Department of Fish and Game.

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

269157

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB2 Monitoring data for Tomales Bay to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the water quality threshold for Mercury. All fish collected between February and July of the same calendar year with a reported length of 50-150 mm were averaged into a single sample, independent of species of trophic level, for comparison with the objective. This LOE consists of a total of 8 fish, which were aggregated into 1 annual averages, consisting of 3 fish species (1 composite(s) of Longjaw Mudsucker each composed of 4 fish per composite, 1 composite(s) of Pacific Staghorn Sculpin each composed of 3 fish per composite, 1 composite(s) of Pacific Staghorn Sculpin each composed of 1 fish per composite). Of these annual averages, 1 average(s), (Year(s): 2019) exceeded the objective.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

Guideline 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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 201WLKD19 (Walker Creek Delta Roar Pickle A).

Temporal Representation:

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

274370

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The evaluation guideline for mercury is 2.1 ug/g (PTI Environmental Services, 1991).

Guideline Reference:

Pollutants of concern in Puget Sound. EPA 910/9-91-003. Seattle, WA: U.S. Environmental Protection Agency

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 201WLKD22 (Walker Creek Delta Roar Island B).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-09-25 to 2018-09-25

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

274262

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The evaluation guideline for mercury is 2.1 ug/g (PTI Environmental Services, 1991).

Guideline Reference:

Pollutants of concern in Puget Sound. EPA 910/9-91-003. Seattle, WA: U.S. Environmental Protection Agency

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 201WLKD10 (Walker Creek Delta Preston B).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-09-25 to 2018-09-25

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

274402

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The evaluation guideline for mercury is 2.1 ug/g (PTI Environmental Services, 1991).

Guideline Reference:

Pollutants of concern in Puget Sound. EPA 910/9-91-003. Seattle, WA: U.S. Environmental Protection Agency

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 201WLKD17 (Walker Creek Delta Roar Mud A).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-09-25 to 2018-09-25

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

307485

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Chemical Concentrations in Fish Tissues from Selected Reservoirs and Coastal Areas in the San Francisco Bay Region. Final Report.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The Statewide Sport Fish Water Quality Objective for the protection of Marine Habitat comes from the Statewide Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California, and is 0.2 mg/Kg wet weight skinless fillet samples of trophic level 3, or trophic level 4 fish (whichever is highest in the water body) over a one year averaging period. If trophic level 3 fish are used in the assessment then the Prey Fish Water Quality Objective must also be used to determine that the Sport Fish Objective is being met. Trophic levels of applicable fish are defined in, but not limited to those in Attachment C of the Final Regulatory Language document (Appendix A) of State Water Resources Control Board Resolution No. 2017-0027.

Guideline 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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): Outer Bay, Mid Bay (Tomales Bay).

Temporal Representation:

Environmental Conditions:

QAPP Information:

Environmental Chemistry Quality Assurance and Data Report for the Toxic Substances Monitoring Program. Department of Fish and Game.

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

274433

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The evaluation guideline for mercury is 2.1 ug/g (PTI Environmental Services, 1991).

Guideline Reference:

Pollutants of concern in Puget Sound. EPA 910/9-91-003. Seattle, WA: U.S. Environmental Protection Agency

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 201WLKD21 (Walker Creek Delta Roar Island A).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-09-25 to 2018-09-25

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

274323

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The evaluation guideline for mercury is 2.1 ug/g (PTI Environmental Services, 1991).

Guideline Reference:

Pollutants of concern in Puget Sound. EPA 910/9-91-003. Seattle, WA: U.S. Environmental Protection Agency

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 201WLKD02 (Walker Creek Delta HP Dock B).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-09-25 to 2018-09-25

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

274304

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The evaluation guideline for mercury is 2.1 ug/g (PTI Environmental Services, 1991).

Guideline Reference:

Pollutants of concern in Puget Sound. EPA 910/9-91-003. Seattle, WA: U.S. Environmental Protection Agency

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 201WLKD01 (Walker Creek Delta HP Dock A).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-09-25 to 2018-09-25

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

274477

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The evaluation guideline for mercury is 2.1 ug/g (PTI Environmental Services, 1991).

Guideline Reference:

Pollutants of concern in Puget Sound. EPA 910/9-91-003. Seattle, WA: U.S. Environmental Protection Agency

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 201WLKD11 (Walker Creek Delta Mid Pickle 1A).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-09-25 to 2018-09-25

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

274456

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The evaluation guideline for mercury is 2.1 ug/g (PTI Environmental Services, 1991).

Guideline Reference:

Pollutants of concern in Puget Sound. EPA 910/9-91-003. Seattle, WA: U.S. Environmental Protection Agency

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 201WLKD18 (Walker Creek Delta Roar Mud B).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-09-25 to 2018-09-25

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

274539

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The evaluation guideline for mercury is 2.1 ug/g (PTI Environmental Services, 1991).

Guideline Reference:

Pollutants of concern in Puget Sound. EPA 910/9-91-003. Seattle, WA: U.S. Environmental Protection Agency

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 201WLKD19 (Walker Creek Delta Roar Pickle A).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-09-25 to 2018-09-25

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

274476

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The evaluation guideline for mercury is 2.1 ug/g (PTI Environmental Services, 1991).

Guideline Reference:

Pollutants of concern in Puget Sound. EPA 910/9-91-003. Seattle, WA: U.S. Environmental Protection Agency

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 201WLKD06 (Walker Creek Delta HP N Flat B).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-09-25 to 2018-09-25

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

274522

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The evaluation guideline for mercury is 2.1 ug/g (PTI Environmental Services, 1991).

Guideline Reference:

Pollutants of concern in Puget Sound. EPA 910/9-91-003. Seattle, WA: U.S. Environmental Protection Agency

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 201WLKD04 (Walker Creek Delta HP S Flat B).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-09-25 to 2018-09-25

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

307494

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Chemical Concentrations in Fish Tissues from Selected Reservoirs and Coastal Areas in the San Francisco Bay Region. Final Report.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The Statewide Sport Fish Water Quality Objective for the protection of the Commercial and Sport Fishing beneficial comes from the Statewide Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California, and is 0.2 mg/Kg wet weight skinless fillet samples of trophic level 3, or trophic level 4 fish (whichever is highest in the water body) over a one year averaging period. Trophic levels of applicable fish are defined in, but not limited to those in Attachment C of the Final Regulatory Language document (Appendix A) of State Water Resources Control Board Resolution No. 2017-0027.

Guideline 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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): Outer Bay, Mid Bay (Tomales Bay).

Temporal Representation:

Environmental Conditions:

QAPP Information:

Environmental Chemistry Quality Assurance and Data Report for the Toxic Substances Monitoring Program. Department of Fish and Game.

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

274575

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The evaluation guideline for mercury is 2.1 ug/g (PTI Environmental Services, 1991).

Guideline Reference:

Pollutants of concern in Puget Sound. EPA 910/9-91-003. Seattle, WA: U.S. Environmental Protection Agency

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 201WLKD24 (Walker Creek Delta Roar Channel B).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-09-25 to 2018-09-25

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

93284

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Many pollutants can accumulate on particles, in sediment, or bioaccumulate in fish and other aquatic organisms. Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The USEPA 304(a) recommended water quality criterion for concentrations of methylmercury in shellfish tissue (wet weight) is 0.2 ppm. (Brodberg, R.K., and G.A. Pollock, 1999; USEPA, 2001)

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Guideline Reference:

Water Quality Criterion for the Protection of Human Health: Methylmercury. Final. United States Environmental Protection Agency Office of Science and Technology Office of Water. EPA-823-R-01-001. January 2001

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site Tomales Bay Spenger's Residence (TBSR).

Temporal Representation:

Representative samples of locally abundant species were collected during the winter on 2/25/2009

Environmental Conditions:

QAPP Information:

Samples were collected as part of the State Water Board's Mussel Watch Program which is a part of the National Oceanic Administration's (NOAAs) National Status and Trends (NS&T). Mussels are shipped to NOAAs contract labs for analysis of trace constituents and mussel condition. Analytical protocols follow those approved by NOAAs NS&T Program Additional background information can be found at:
http://ccma.nos.noaa.gov/stressors/pollution/nsandt/

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 152861, Mercury	Region 2
Tomales Bay

LOE ID:

274504

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Marine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The evaluation guideline for mercury is 2.1 ug/g (PTI Environmental Services, 1991).

Guideline Reference:

Pollutants of concern in Puget Sound. EPA 910/9-91-003. Seattle, WA: U.S. Environmental Protection Agency

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 201WLKD23 (Walker Creek Delta Roar Channel A).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-09-25 to 2018-09-25

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.


DECISION ID	154558	Region 2
Tomales Bay

Pollutant:	PAHs (Polycyclic Aromatic Hydrocarbons)
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

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 the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 154558, PAHs (Polycyclic Aromatic Hydrocarbons)	Region 2
Tomales Bay

LOE ID:

315235

Pollutant:

PAHs (Polycyclic Aromatic Hydrocarbons)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

The result did not exceed the guideline. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal. The total PAHs were calculated as the potency equivalency concentration or the sum of the toxic equivalency factors multiplied by the concentrations of: Acenaphthene, Acenaphthylene, Anthracene, Benz[a]anthracene, Benzo[a]pyrene, Benzo[b]fluoranthene, Benzo[g,h,i]perylene, Benzo[k]fluoranthene, Dibenzo[a,h]anthracene, Chrysene, Fluoranthene, Fluorene, Indeno[1,2,3-c,d]pyrene, Phenanthrene, and Pyrene.

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

OEHHA published a risk-based concentration protective of public health for the concentration of PAH in San Francisco Bay fish and shellfish following the M/V Cosco Busan oil spill. OEHHA determined that a concentration of 43.7 ppb (wet weight) would result in one expected additional cancer case for a population of 10,000 individuals consuming one meal per week of San Francisco Bay fish or shellfish. This calculated concentration assumes an average body weight of 70 kg and a consumption rate of 32.5 g/day for a 30-year exposure over a 70-year lifetime (OEHHA 2007).

Guideline Reference:

Report on the Safety of Consuming Fish and Shellfish from Areas Impacted by the M/V Cosco Busan Oil Spill in San Francisco Bay, California (OEHHA, 2007)

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site Tomales Bay Spenger's Residence (TBSR).

Temporal Representation:

Representative samples of locally abundant species were collected during the winter on 2/25/2009

Environmental Conditions:

QAPP Information:

Samples were collected as part of the State Water Board's Mussel Watch Program which is a part of the National Oceanic Administration's (NOAAs) National Status and Trends (NS&T). Mussels are shipped to NOAAs contract labs for analysis of trace constituents and mussel condition. Analytical protocols follow those approved by NOAAs NS&T Program Additional background information can be found at: http://ccma.nos.noaa.gov/stressors/pollution/nsandt/

QAPP Information Reference(s):

Major and Trace Element Analytical Methods of the National Status and Trends Program: 2000-2006.


DECISION ID	98474	Region 2
Tomales Bay

Pollutant:	Arsenic
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 3.5 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of one sample exceeds the guideline. 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 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. The one sample did not exceed the guideline and 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 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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 98474, Arsenic	Region 2
Tomales Bay

LOE ID:

93265

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

The one sample did not exceed the guideline. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal. The fraction of total arsenic in inorganic form was taken to be 0.115%, which was the maximum fraction of inorganic arsenic found in shellfish tissue from SF Bay. This number was screened against the guideline.

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

Contaminant Concentrations in Fish from San Francisco Bay, 2000

Calculating Fraction of Inorganic Arsenic in SF Bay Fish and Shellfish

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The modified OEHHA Advisory Tissue Level for arsenic in shellfish tissue is 0.52 ppm. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in ten thousand. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; OEHHA, 2004)

Advisory Tissue Levels (ATLs), while still conferring no significant health risk to
individuals consuming sport fish in the quantities shown over a lifetime, were developed
with the recognition that there are unique health benefits associated with fish
consumption and that the advisory process should be expanded beyond a simple risk
paradigm in order to best promote the overall health of the fish consumer. ATLs provide
a number of recommended fish servings that correspond to the range of contaminant
concentrations found in fish and are used to provide consumption advice to prevent
consumers from being exposed to more than the average daily reference dose for noncarcinogens
or to a risk level greater than 1x10-4 for carcinogens (not more than one
additional cancer case in a population of 10,000 people consuming fish at the given
consumption rate over a lifetime). ATLs are designed to encourage consumption of fish
that can be eaten in quantities likely to provide significant health benefits, while
discouraging consumption of fish that, because of contaminant concentrations, should not
be eaten or cannot be eaten in amounts recommended for improving overall health (eight
ounces total, prior to cooking, per week). ATLs are one of the criteria that will be used
by OEHHA for issuing fish consumption guidelines.

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site Tomales Bay Spenger's Residence (TBSR).

Temporal Representation:

Representative samples of locally abundant species were collected during the winter on 2/25/2009

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	98187	Region 2
Tomales Bay

Pollutant:	Cadmium
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 3.5 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of one sample exceeds the guideline. 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 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. The one sample did not exceed the guideline and 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 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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 98187, Cadmium	Region 2
Tomales Bay

LOE ID:

93266

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for cadmium in shellfish tissue is 3.3 ppm. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; USEPA, 2000)

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site Tomales Bay Spenger's Residence (TBSR).

Temporal Representation:

Representative samples of locally abundant species were collected during the winter on 2/25/2009

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	98738	Region 2
Tomales Bay

Pollutant:	Chlordane
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 3.5 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of one sample exceeds the guideline. 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 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. The one sample did not exceed the guideline and 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 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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 98738, Chlordane	Region 2
Tomales Bay

LOE ID:

93270

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for total chlordane in shellfish tissue is 6.0 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008)

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site Tomales Bay Spenger's Residence (TBSR).

Temporal Representation:

Representative samples of locally abundant species were collected during the winter on 2/25/2009

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	98739	Region 2
Tomales Bay

Pollutant:	Chlorpyrifos
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 3.5 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of one sample exceeds the guideline. 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 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. The one sample did not exceed the guideline and 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 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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 98739, Chlorpyrifos	Region 2
Tomales Bay

LOE ID:

93271

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for chlorpyrifos in shellfish tissue is 1,000 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; USEPA, 2000)

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site Tomales Bay Spenger's Residence (TBSR).

Temporal Representation:

Representative samples of locally abundant species were collected during the winter on 2/25/2009

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	98032	Region 2
Tomales Bay

Pollutant:	DDT (Dichlorodiphenyltrichloroethane)
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 3.5 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of one sample exceeds the guideline. 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 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. The one sample did not exceed the guideline and 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 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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 98032, DDT (Dichlorodiphenyltrichloroethane)	Region 2
Tomales Bay

LOE ID:

93291

Pollutant:

Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for total DDT in shellfish tissue is 23 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008)

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site Tomales Bay Spenger's Residence (TBSR).

Temporal Representation:

Representative samples of locally abundant species were collected during the winter on 2/25/2009

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	97975	Region 2
Tomales Bay

Pollutant:	Dieldrin
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 3.5 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of zero sample exceeds the guideline. 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 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. It is not known if the sample exceeds the guideline. 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 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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 97975, Dieldrin	Region 2
Tomales Bay

LOE ID:

93272

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

The detected not quantifiable result was not included in the assessment since the reporting limit was above the evaluation guideline. MDL were provided by NOAA Federal and RL were calculated by multiplying 3.18 by the MDL.

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for dieldrin in shellfish tissue is 0.49 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008)

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site Tomales Bay Spenger's Residence (TBSR).

Temporal Representation:

Representative samples of locally abundant species were collected during the winter on 2/25/2009

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	97868	Region 2
Tomales Bay

Pollutant:	Endosulfan
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 3.5 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of one sample exceeds the guideline. 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 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. The one sample did not exceed the guideline and 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 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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 97868, Endosulfan	Region 2
Tomales Bay

LOE ID:

93276

Pollutant:

Endosulfan

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for endosulfan (l and ll) in shellfish tissue is 20,000 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; USEPA, 2000)

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site Tomales Bay Spenger's Residence (TBSR).

Temporal Representation:

Representative samples of locally abundant species were collected during the winter on 2/25/2009

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	97869	Region 2
Tomales Bay

Pollutant:	Endrin
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 3.5 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of one sample exceeds the guideline. 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 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. The one sample did not exceed the guideline and 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 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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 97869, Endrin	Region 2
Tomales Bay

LOE ID:

93277

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for endrin in shellfish tissue is 1,000 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; USEPA, 2000)

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site Tomales Bay Spenger's Residence (TBSR).

Temporal Representation:

Representative samples of locally abundant species were collected during the winter on 2/25/2009

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	97870	Region 2
Tomales Bay

Pollutant:	Heptachlor epoxide
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 3.5 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of one sample exceeds the guideline. 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 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. The one sample did not exceed the guideline and 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 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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 97870, Heptachlor epoxide	Region 2
Tomales Bay

LOE ID:

93278

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

The results did not exceed the guideline. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal.

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for heptachlor epoxide in shellfish tissue is 1.4 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; OEHHA, 1999)

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Public Health Goal for Heptachlor and Heptachlor Epoxide in Drinking Water

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site Tomales Bay Spenger's Residence (TBSR).

Temporal Representation:

Representative samples of locally abundant species were collected during the winter on 2/25/2009

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	97871	Region 2
Tomales Bay

Pollutant:	Hexachlorobenzene/ HCB
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 3.5 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of one sample exceeds the guideline. 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 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. The one sample did not exceed the guideline and 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 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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 97871, Hexachlorobenzene/ HCB	Region 2
Tomales Bay

LOE ID:

93282

Pollutant:

Hexachlorobenzene/ HCB

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for hexachlorobenzene in shellfish tissue is 4.3 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; OEHHA, 2005)

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site Tomales Bay Spenger's Residence (TBSR).

Temporal Representation:

Representative samples of locally abundant species were collected during the winter on 2/25/2009

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	98188	Region 2
Tomales Bay

Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
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 3.5 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of one samples exceed the OEHHA guideline. 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. Zero of one samples exceed the OEHHA guideline and 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 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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 98188, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 2
Tomales Bay

LOE ID:

93283

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for lindane in shellfish tissue is 7.1 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; OEHHA, 2005)

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site Tomales Bay Spenger's Residence (TBSR).

Temporal Representation:

Representative samples of locally abundant species were collected during the winter on 2/25/2009

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	98595	Region 2
Tomales Bay

Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
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 3.5 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of one sample exceeds the guideline. 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 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. The one sample did not exceed the guideline and 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 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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 98595, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 2
Tomales Bay

LOE ID:

93283

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site Tomales Bay Spenger's Residence (TBSR).

Temporal Representation:

Representative samples of locally abundant species were collected during the winter on 2/25/2009

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	97976	Region 2
Tomales Bay

Pollutant:	Mirex
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 3.5 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of zero sample exceeds the guideline. 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 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. It is not known if the sample exceeds the guideline. 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 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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 97976, Mirex	Region 2
Tomales Bay

LOE ID:

93287

Pollutant:

Mirex

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

The non detect result was not included in the assessment since the reporting limit was above the evaluation guideline. MDL were provided by NOAA Federal and RL were calculated by multiplying 3.18 by the MDL.

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for mirex in shellfish tissue is 0.43 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008; OEHHA, 1992)

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Expedited Cancer Potency Values and Proposed Regulatory Levels for Certain Proposition 65 Carcinogens.

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site Tomales Bay Spenger's Residence (TBSR).

Temporal Representation:

Representative samples of locally abundant species were collected during the winter on 2/25/2009

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	98030	Region 2
Tomales Bay

Pollutant:	PCBs (Polychlorinated biphenyls)
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 3.5 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. One of one sample exceeds the guideline. 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 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. The one sample did exceed the guideline and 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 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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 98030, PCBs (Polychlorinated biphenyls)	Region 2
Tomales Bay

LOE ID:

93289

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

The result did exceed the guideline. Data were reported on a dry weight basis and were converted to a wet weight basis by multiplying the dry-weight concentration by a factor of 1 minus the percentage of moisture content expressed as a decimal. Total PCB was assessed for as follows: PCB aroclors and congeners were summed separately and the sum that yielded the highest value was used for the assessment.

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for polychlorinated biphenyls in shellfish tissue is 3.9 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008)

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site Tomales Bay Spenger's Residence (TBSR).

Temporal Representation:

Representative samples of locally abundant species were collected during the winter on 2/25/2009

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	98031	Region 2
Tomales Bay

Pollutant:	Selenium
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 3.5 of the Listing Policy. Under section 3.5 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of one sample exceeds the guideline. 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 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. The one sample did not exceed the guideline and 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 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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 98031, Selenium	Region 2
Tomales Bay

LOE ID:

93290

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Shellfish

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

Shellfish surveys

Data Used to Assess Water Quality:

Data Reference:

State Mussel Watch Program Data 1977-2000; Winter 2007-Winter 2009. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for selenium in shellfish tissue is 11 ppm. This screening level assumes an average body weight of 70 kg and a consumption rate of 21 g/day. A background dietary consumption rate of 0.114 mg/day is applied for this micronutrient. (Brodberg, R.K., and G.A. Pollock, 1999; Klasing, S., and R. Brodberg, 2008)

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Samples are collected by hand from three sub-locations for each site. The composite samples were collected from site Tomales Bay Spenger's Residence (TBSR).

Temporal Representation:

Representative samples of locally abundant species were collected during the winter on 2/25/2009

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):