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

Supporting Information

Regional Board 2 - San Francisco Bay Region

Water Body Name:	Pacific Ocean at Agate Beach (Marin County)
Water Body ID:	CAC2013000020210712029120
Water Body Type:	Coastal & Bay Shoreline


DECISION ID	151052	Region 2
Pacific Ocean at Agate Beach (Marin County)

Pollutant:	Ammonia
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
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 151052, Ammonia	Region 2
Pacific Ocean at Agate Beach (Marin County)

LOE ID:

278395

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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 ASBS Regional Reference Site Monitoring data for Pacific Ocean at Agate Beach (Marin County) to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California's Ocean Plan, Table 3 lists the 6-month median concentration of 600 ug/L for ammonia (as nitrogen) to protect aquatic life in marine waters.

Objective/Criterion Reference:

SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 402MAR010-REC (Trailhead at Agate Beach - Receiving Water).

Temporal Representation:

The samples were collected between the dates of 2014-02-26 and 2016-01-05

Environmental Conditions:

QAPP Information:

Southern California Coastal Water Research Project. 2008. Assessing Natural Water Quality In Areas Of Special Biological Significance.

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	144672	Region 2
Pacific Ocean at Agate Beach (Marin County)

Pollutant:	Arsenic
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 144672, Arsenic	Region 2
Pacific Ocean at Agate Beach (Marin County)

LOE ID:

279954

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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 ASBS Regional Reference Site Monitoring data for Pacific Ocean at Agate Beach (Marin County) to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Arsenic.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California's Ocean Plan, Table 3 lists the 6-month median concentration of 8 ug/L for total arsenic to protect aquatic life in marine waters.

Objective/Criterion Reference:

SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 402MAR010-REC (Trailhead at Agate Beach - Receiving Water).

Temporal Representation:

The samples were collected between the dates of 2014-02-26 and 2016-01-05

Environmental Conditions:

QAPP Information:

Southern California Coastal Water Research Project. 2008. Assessing Natural Water Quality In Areas Of Special Biological Significance.

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	144673	Region 2
Pacific Ocean at Agate Beach (Marin County)

Pollutant:	Cadmium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 144673, Cadmium	Region 2
Pacific Ocean at Agate Beach (Marin County)

LOE ID:

280461

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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 ASBS Regional Reference Site Monitoring data for Pacific Ocean at Agate Beach (Marin County) to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Cadmium.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California's Ocean Plan, Table 3 lists the 6-month median concentration of 1 ug/L for total cadmium to protect aquatic life in marine waters.

Objective/Criterion Reference:

SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 402MAR010-REC (Trailhead at Agate Beach - Receiving Water).

Temporal Representation:

The samples were collected between the dates of 2014-02-26 and 2016-01-05

Environmental Conditions:

QAPP Information:

Southern California Coastal Water Research Project. 2008. Assessing Natural Water Quality In Areas Of Special Biological Significance.

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	144674	Region 2
Pacific Ocean at Agate Beach (Marin County)

Pollutant:	Copper
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 144674, Copper	Region 2
Pacific Ocean at Agate Beach (Marin County)

LOE ID:

283301

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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 ASBS Regional Reference Site Monitoring data for Pacific Ocean at Agate Beach (Marin County) to determine beneficial use support and results are as follows: 1 of 3 samples exceeded the water quality threshold for Copper.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California's Ocean Plan, Table 3 lists the 6-month median concentration of 3 ug/L for total copper to protect aquatic life in marine waters.

Objective/Criterion Reference:

SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 402MAR010-REC (Trailhead at Agate Beach - Receiving Water).

Temporal Representation:

The samples were collected between the dates of 2014-02-26 and 2016-01-05

Environmental Conditions:

QAPP Information:

Southern California Coastal Water Research Project. 2008. Assessing Natural Water Quality In Areas Of Special Biological Significance.

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	144675	Region 2
Pacific Ocean at Agate Beach (Marin County)

Pollutant:	Fluoranthene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 144675, Fluoranthene	Region 2
Pacific Ocean at Agate Beach (Marin County)

LOE ID:

283907

Pollutant:

Fluoranthene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ASBS Regional Reference Site Monitoring data for Pacific Ocean at Agate Beach (Marin County) to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Fluoranthene.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California's Ocean Plan, Table 3 lists the 30-day average concentration of 15 ug/L for fluoranthene to protect human health in marine waters.

Objective/Criterion Reference:

SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 402MAR010-REC (Trailhead at Agate Beach - Receiving Water).

Temporal Representation:

The samples were collected between the dates of 2013-11-20 and 2015-04-07

Environmental Conditions:

QAPP Information:

Southern California Coastal Water Research Project. 2008. Assessing Natural Water Quality In Areas Of Special Biological Significance.

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	150269	Region 2
Pacific Ocean at Agate Beach (Marin County)

Pollutant:	Indicator Bacteria
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
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 150269, Indicator Bacteria	Region 2
Pacific Ocean at Agate Beach (Marin County)

LOE ID:

299620

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ASBS Regional Reference Site Monitoring data for Pacific Ocean at Agate Beach (Marin County) to determine beneficial use support and the results are as follows: 2 of the 3 samples exceeded the Statistical Threshold Value (STV) water quality threshold for Enterococcus. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The bacteria water quality objective to protect the REC-1 beneficial use in ocean waters, applies a Statistical Threshold Value to enterococcus of 110 cfu/100 mL, not to be exceeded by more than 10 percent of samples collected within in a calendar month. (Ocean Plan 2019)

Objective/Criterion Reference:

SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 402MAR010-REC (Trailhead at Agate Beach - Receiving Water).

Temporal Representation:

The samples were collected between the days of 2015-04-07 and 2016-01-05 .

Environmental Conditions:

QAPP Information:

Southern California Coastal Water Research Project. 2008. Assessing Natural Water Quality In Areas Of Special Biological Significance.

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 150269, Indicator Bacteria	Region 2
Pacific Ocean at Agate Beach (Marin County)

LOE ID:

299643

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

0.1

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 ASBS Regional Reference Site Monitoring data for Pacific Ocean at Agate Beach (Marin County) to determine beneficial use support and the results are as follows: 1 of the 3 samples exceeded the water quality threshold for Coliform, Total. The water quality threshold is based on a 10% exceedance rate that is calculated for a 30-Day peroid.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The bacteria water quality objective to protect the shellfish beneficial use in ocean waters applies a threshold of 230 per 100 mL for total coliform, not to be exceeded by more than 10 percent of samples. (Ocean Plan 2019)

Objective/Criterion Reference:

SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 402MAR010-REC (Trailhead at Agate Beach - Receiving Water).

Temporal Representation:

The samples were collected between the days of 2015-02-05 and 2015-04-07 .

Environmental Conditions:

QAPP Information:

Southern California Coastal Water Research Project. 2008. Assessing Natural Water Quality In Areas Of Special Biological Significance.

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 150269, Indicator Bacteria	Region 2
Pacific Ocean at Agate Beach (Marin County)

LOE ID:

299618

Pollutant:

Total 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 ASBS Regional Reference Site Monitoring data for Pacific Ocean at Agate Beach (Marin County) to determine beneficial use support and the results are as follows: 1 of the 3 samples exceeded the water quality threshold for Coliform, Total. The water quality threshold for shellfish is based on the median concentration of Total Coliform at each station, and is calculated as a 30-day rolling median.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

In order to protect the shellfish benefical use in ocean waters, the median total coliform concentration shall not exceed 70 per 100 mL. (Ocean Plan 2019)

Objective/Criterion Reference:

SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 402MAR010-REC (Trailhead at Agate Beach - Receiving Water).

Temporal Representation:

The samples were collected between the days of 2015-02-05 and 2015-04-07 .

Environmental Conditions:

QAPP Information:

Southern California Coastal Water Research Project. 2008. Assessing Natural Water Quality In Areas Of Special Biological Significance.

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 150269, Indicator Bacteria	Region 2
Pacific Ocean at Agate Beach (Marin County)

LOE ID:

299641

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

SSM

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ASBS Regional Reference Site Monitoring data for Pacific Ocean at Agate Beach (Marin County) to determine beneficial use support and the results are as follows: 1 of the 4 samples exceeded the water quality threshold for Coliform, Fecal. The water quality threshold is based on a Single Sample Maximum (SSM) value that is calculated daily.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The bacteria water quality objective to protect the REC-1 beneficial use in ocean waters applies a single sample maximum of fecal coliform, not to exceed 400 per 100 mL. (Ocean Plan 2019)

Objective/Criterion Reference:

SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 402MAR010-REC (Trailhead at Agate Beach - Receiving Water).

Temporal Representation:

The samples were collected between the days of 2015-04-06 and 2016-01-05 .

Environmental Conditions:

QAPP Information:

Southern California Coastal Water Research Project. 2008. Assessing Natural Water Quality In Areas Of Special Biological Significance.

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	144676	Region 2
Pacific Ocean at Agate Beach (Marin County)

Pollutant:	Lead
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 144676, Lead	Region 2
Pacific Ocean at Agate Beach (Marin County)

LOE ID:

284243

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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 ASBS Regional Reference Site Monitoring data for Pacific Ocean at Agate Beach (Marin County) to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Lead.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California's Ocean Plan, Table 3 lists the 6-month median concentration of 2 ug/L for total lead to protect aquatic life in marine waters.

Objective/Criterion Reference:

SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 402MAR010-REC (Trailhead at Agate Beach - Receiving Water).

Temporal Representation:

The samples were collected between the dates of 2014-02-26 and 2016-01-05

Environmental Conditions:

QAPP Information:

Southern California Coastal Water Research Project. 2008. Assessing Natural Water Quality In Areas Of Special Biological Significance.

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	145456	Region 2
Pacific Ocean at Agate Beach (Marin County)

Pollutant:	Mercury
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 145456, Mercury	Region 2
Pacific Ocean at Agate Beach (Marin County)

LOE ID:

284700

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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 ASBS Regional Reference Site Monitoring data for Pacific Ocean at Agate Beach (Marin County) to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Mercury.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California's Ocean Plan, Table 3 lists the 6-month median concentration of 0.04 ug/L for total mercury to protect aquatic life in marine waters.

Objective/Criterion Reference:

SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 402MAR010-REC (Trailhead at Agate Beach - Receiving Water).

Temporal Representation:

The samples were collected between the dates of 2014-02-26 and 2016-01-05

Environmental Conditions:

QAPP Information:

Southern California Coastal Water Research Project. 2008. Assessing Natural Water Quality In Areas Of Special Biological Significance.

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	144677	Region 2
Pacific Ocean at Agate Beach (Marin County)

Pollutant:	Nickel
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 144677, Nickel	Region 2
Pacific Ocean at Agate Beach (Marin County)

LOE ID:

284736

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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 ASBS Regional Reference Site Monitoring data for Pacific Ocean at Agate Beach (Marin County) to determine beneficial use support and results are as follows: 1 of 3 samples exceeded the water quality threshold for Nickel.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California's Ocean Plan, Table 3 lists the 6-month median concentration of 5 ug/L for total nickel to protect aquatic life in marine waters.

Objective/Criterion Reference:

SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 402MAR010-REC (Trailhead at Agate Beach - Receiving Water).

Temporal Representation:

The samples were collected between the dates of 2014-02-26 and 2016-01-05

Environmental Conditions:

QAPP Information:

Southern California Coastal Water Research Project. 2008. Assessing Natural Water Quality In Areas Of Special Biological Significance.

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	149013	Region 2
Pacific Ocean at Agate Beach (Marin County)

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:	New Decision
Revision Status	Revised
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 3.1 of the Listing Policy. Under section 3.1 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. Three of three samples exceed the PAH evaluation guideline, which is the Ocean Plan's water column objective of 0.0088 ug/L. However, there are limitations in the data that undermine the support for an impairment determination. First, a water column number is being used as a proxy for a shellfish tissue concentration. The concentration in water has been related, using conservative assumptions, to a tissue concentration. However, in the absence of site-specific data to establish what this relationship is at Agate Beach, there is considerable uncertainty in relying on a water concentration to represent a tissue concentration in shellfish. Second, only three (anthracene, pyrene, and phenanthrene) PAH species were ever detected in site water for any sampling date, and none of these three species were detected in water on more than 40% of the sampling dates. Third, there is not a consistent pattern of sufficiently high concentrations of the PAH species. In fact, three of the four phenanthrene detections and two of the three pyrene detections are at or near the upper range of the detection limit; Very few of even the detectable data are substantially higher than the detection limit. Last, for tissue and sediment water quality assessments, PAH species concentrations are weighted by a toxicity equivalency factor that normalizes the PAH species toxicity to that of Benzo(a) pyrene, which has a weight of 1. These weighted concentrations are then summed prior to comparison to an objective or evaluation guideline. In this case, the Ocean Plan simply requires summing the PAH species, irrespective of toxicity differences. The detected PAH species are not among the most toxic PAH chemicals. A specific concentration of benzo(a) pyrene is 100 times more toxic than anthracene and 1000 times more toxic than the same concentration of phenanthrene and pyrene. Based on the readily available data and information, the weight of evidence indicates that there is not sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. Consideration to place a waterbody segment on the 303(d) list or to determine that the beneficial use is fully supported requires further data and information to increase the confidence in the accuracy of the threshold and the representativeness of the submitted data. Assessment of the shellfish harvesting beneficial use logically should make use of PAH concentration data in shellfish tissue.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 149013, PAHs (Polycyclic Aromatic Hydrocarbons)	Region 2
Pacific Ocean at Agate Beach (Marin County)

LOE ID:

289095

Pollutant:

PAHs (Polycyclic Aromatic Hydrocarbons)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Shellfish Harvesting

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ASBS Regional Reference Site Monitoring data for Pacific Ocean at Agate Beach (Marin County) to determine beneficial use support and the results are as follows: 3 of the 3 samples exceeded the water quality threshold for Total PAHs. Although a total of 6 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California's Ocean Plan, Table 3 lists the 30-day average concentration of 0.0088 ug/L for PAHs to protect human health in marine waters.

Objective/Criterion Reference:

SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (402MAR010-REC).

Temporal Representation:

Data for this waterbody was collected over the date range 2013-11-20 to 2015-04-07

Environmental Conditions:

QAPP Information:

Southern California Coastal Water Research Project. 2008. Assessing Natural Water Quality In Areas Of Special Biological Significance.

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	144678	Region 2
Pacific Ocean at Agate Beach (Marin County)

Pollutant:	Selenium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 144678, Selenium	Region 2
Pacific Ocean at Agate Beach (Marin County)

LOE ID:

287922

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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 ASBS Regional Reference Site Monitoring data for Pacific Ocean at Agate Beach (Marin County) to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Selenium.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California's Ocean Plan, Table 3 lists the 6-month median concentration of 15 ug/L for total selenium to protect aquatic life in marine waters.

Objective/Criterion Reference:

SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 402MAR010-REC (Trailhead at Agate Beach - Receiving Water).

Temporal Representation:

The samples were collected between the dates of 2014-02-26 and 2016-01-05

Environmental Conditions:

QAPP Information:

Southern California Coastal Water Research Project. 2008. Assessing Natural Water Quality In Areas Of Special Biological Significance.

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	144679	Region 2
Pacific Ocean at Agate Beach (Marin County)

Pollutant:	Silver
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 144679, Silver	Region 2
Pacific Ocean at Agate Beach (Marin County)

LOE ID:

287959

Pollutant:

Silver

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved silver criterion maximum concentration (CMC) to protect aquatic life in saltwater is 1.9 ug/L. This criterion was divided by 2 in order to better represent a CMC value as specified in footnote g of Table (b)(1) of the California Toxics Rule, 2000.

Objective/Criterion Reference:

SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 402MAR010-REC (Trailhead at Agate Beach - Receiving Water).

Temporal Representation:

The samples were collected between the dates of 2014-02-26 and 2015-04-07

Environmental Conditions:

QAPP Information:

Southern California Coastal Water Research Project. 2008. Assessing Natural Water Quality In Areas Of Special Biological Significance.

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	144680	Region 2
Pacific Ocean at Agate Beach (Marin County)

Pollutant:	Zinc
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 144680, Zinc	Region 2
Pacific Ocean at Agate Beach (Marin County)

LOE ID:

289929

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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 ASBS Regional Reference Site Monitoring data for Pacific Ocean at Agate Beach (Marin County) to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Zinc.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California's Ocean Plan, Table 3 lists the 6-month median concentration of 20 ug/L for total zinc to protect aquatic life in marine waters.

Objective/Criterion Reference:

SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 402MAR010-REC (Trailhead at Agate Beach - Receiving Water).

Temporal Representation:

The samples were collected between the dates of 2014-02-26 and 2016-01-05

Environmental Conditions:

QAPP Information:

Southern California Coastal Water Research Project. 2008. Assessing Natural Water Quality In Areas Of Special Biological Significance.

QAPP Information Reference(s):

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