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

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name:	McGrath Beach
Water Body ID:	CAX4031100019990923094745
Water Body Type:	Coastal & Bay Shoreline


DECISION ID	150557	Region 4
McGrath Beach

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:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)(2018)
Revision Status	Revised
Sources:	Nonpoint Source
TMDL Name:	McGrath Beach Coliform
TMDL Project Code:	225
Date TMDL Approved by USEPA:	11/20/2003
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, 4.3 and 4.11 of the Listing Policy. Under section 4.3 of the Policy, a minimum of one line of evidence is needed to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Because a statistically sufficient number of geomean samples were not available, attainment of the bacteria objective was determined based only on the STV per the situation-specific weight of evidence approach outlined in Section 4.11 of the Listing Policy. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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. 0 of 1 sample exceeded the statistical threshold value for Enterococcus and this is insufficient to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. 4. The McGrath Beach Coliform TMDL was approved by USEPA on 11/20/2003. 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 there was a previous listing and there are not enough data to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy.

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 150557, Indicator Bacteria	Region 4
McGrath Beach

LOE ID:

86521

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

306

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed BW data for McGrath Beach to determine beneficial use support and results are as follows: 6 of 306 samples exceed the criterion for Enterococci.

Data Reference:

Data for Region 4 Beach Watch.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California Ocean Plan (SWRCB 2009) single sample maximum states that enterococcus density shall not exceed 104 per 100 mL.

Objective/Criterion Reference:

California Ocean Plan Water Quality Control Plan Ocean Waters of California 2009

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for McGrath Beach was collected at 3 monitoring sites [ McGrath State Beach (#26000), McGrath State Beach (#28000), McGrath State Beach (#27000)]

Temporal Representation:

Data was collected over the time period 4/4/2005-9/30/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The samples were collected for the Beach Watch program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 150557, Indicator Bacteria	Region 4
McGrath Beach

LOE ID:

86527

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

257

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

six of the 257 geomeans exceeded the total coliform objective. The samples were collected during dry weather from April through October only. According to the listing Policy section 3.3 a four percent exceedance frequency should be used.

Data Reference:

Data for Region 4 Beach Watch.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The geometric mean standard for total coliform states that the fecal coliform density shall not exceed 1000 per 100 mL. Water Quality Control Plan for Ocean Waters 2009.

Objective/Criterion Reference:

California Ocean Plan Water Quality Control Plan Ocean Waters of California 2009

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from McGrath State Beach (#26000, #27000 and #28000).

Temporal Representation:

Samples were collected approximately once a week from 2005 to 2008.

Environmental Conditions:

QAPP Information:

The samples were collected for the Beach Watch program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 150557, Indicator Bacteria	Region 4
McGrath Beach

LOE ID:

3524

Pollutant:

Coliform Bacteria

LOE Subgroup:

Narrative Description Data

Matrix:

Not Specified

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

A TMDL was approved by USEPA on November 20, 2003. The RWQCB is implementing the TMDL through a Cleanup and Abatement Order.

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 150557, Indicator Bacteria	Region 4
McGrath Beach

LOE ID:

302152

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 BeachWatch_Ventura County data for McGrath Beach to determine beneficial use support and the results are as follows: 0 of the 1 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. This data is for an AB411 beach. This LOE specifically corresponds with dry weather samples and only includes samples collected between April 1 and October 31 of each year.

Data Reference:

WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 4.

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): 27000 (27000-McGrath State Beach, Ventura).

Temporal Representation:

The samples were collected between the days of 2014-09-09 and 2014-09-15 .

Environmental Conditions:

QAPP Information:

State Board Staff. 2021. QAPP Reference for Beach Watch Program.

QAPP Information Reference(s):

QAPP Reference for Beach Watch Program

Line of Evidence (LOE) for Decision ID 150557, Indicator Bacteria	Region 4
McGrath Beach

LOE ID:

86522

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

257

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

One of the 257 geomeans exceeded the entercoccus objective. The samples were collected during dry weather from April through October only. According to the listing Policy section 3.3 a four percent exceedance frequency should be used.

Data Reference:

Data for Region 4 Beach Watch.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The geometric mean standard for enterococcus states that the fecal coliform density shall not exceed 35 per 100 mL. Water Quality Control Plan for Ocean Waters 2009.

Objective/Criterion Reference:

California Ocean Plan Water Quality Control Plan Ocean Waters of California 2009

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from McGrath State Beach (#26000, #27000 and #28000).

Temporal Representation:

Samples were collected approximately once a week from 2005 to 2008.

Environmental Conditions:

QAPP Information:

The samples were collected for the Beach Watch program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 150557, Indicator Bacteria	Region 4
McGrath Beach

LOE ID:

86523

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

306

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed BW data for McGrath Beach to determine beneficial use support and results are as follows: 3 of 306 samples exceed the criterion for Coliform, Fecal.

Data Reference:

Data for Region 4 Beach Watch.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California Ocean Plan (SWRCB 2009) single sample maximum states that fecal coliform density shall not exceed 400 per 100ml

Objective/Criterion Reference:

California Ocean Plan Water Quality Control Plan Ocean Waters of California 2009

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for McGrath Beach was collected at 3 monitoring sites [ McGrath State Beach (#26000), McGrath State Beach (#28000), McGrath State Beach (#27000)]

Temporal Representation:

Data was collected over the time period 4/4/2005-9/30/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The samples were collected for the Beach Watch program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 150557, Indicator Bacteria	Region 4
McGrath Beach

LOE ID:

86524

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

257

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Zero of the 257 geomeans exceeded the fecal coliform objective. The samples were collected during dry weather from April through October only. According to the listing Policy section 3.3 a four percent exceedance frequency should be used.

Data Reference:

Data for Region 4 Beach Watch.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The geometric mean standard for fecal coliform states that the fecal coliform density shall not exceed 200 per 100 mL. Water Quality Control Plan for Ocean Waters 2009.

Objective/Criterion Reference:

California Ocean Plan Water Quality Control Plan Ocean Waters of California 2009

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from McGrath State Beach (#26000, #27000 and #28000).

Temporal Representation:

Samples were collected approximately once a week from 2005 to 2008.

Environmental Conditions:

QAPP Information:

The samples were collected for the Beach Watch program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 150557, Indicator Bacteria	Region 4
McGrath Beach

LOE ID:

86525

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Shellfish Harvesting

Number of Samples:

306

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed bw data for McGrath Beach to determine beneficial use support and results are as follows: 99 of 306 samples exceed the criterion for Coliform, Total.

Data Reference:

Data for Region 4 Beach Watch.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Ocean Plan (2009) states the following: At all areas where shellfish may be harvested for human consumption, the following bacterial objectives shall be maintained throughout the water column: Ten percent of the samples collected during any 30-day period shall not exceed 230 MPN/100mL.

Objective/Criterion Reference:

California Ocean Plan Water Quality Control Plan Ocean Waters of California 2009

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for McGrath Beach was collected at 3 monitoring sites [ McGrath State Beach (#26000), McGrath State Beach (#28000), McGrath State Beach (#27000)]

Temporal Representation:

Data was collected over the time period 4/4/2005-9/30/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The samples were collected for the Beach Watch program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 150557, Indicator Bacteria	Region 4
McGrath Beach

LOE ID:

86526

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

306

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed BW data for McGrath Beach to determine beneficial use support and results are as follows: 4 of 306 samples exceed the criterion for Coliform, Total.

Data Reference:

Data for Region 4 Beach Watch.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California Ocean Plan (2009) single sample maximum states that total coliform density shall not exceed 10,000 per 100 mL

Objective/Criterion Reference:

California Ocean Plan Water Quality Control Plan Ocean Waters of California 2009

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for McGrath Beach was collected at 3 monitoring sites [ McGrath State Beach (#26000), McGrath State Beach (#28000), McGrath State Beach (#27000)]

Temporal Representation:

Data was collected over the time period 4/4/2005-9/30/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The samples were collected for the Beach Watch program.

QAPP Information Reference(s):