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

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name:	Marina del Rey Harbor Beach
Water Body ID:	CAX4051700019990923093513
Water Body Type:	Coastal & Bay Shoreline


DECISION ID	150312	Region 4
Marina del Rey Harbor 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:	Marina del Rey Pathogens (46)
TMDL Project Code:	232
Date TMDL Approved by USEPA:	03/18/2004
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 4.3 of the Listing Policy. Under Section 4.3 of the Policy, a minimum of one line of evidence is needed to assess listing status. 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. 14 of 18 samples exceeded the geometric mean for Enterococcus and these exceed the allowable frequency listed in Table 4.2 of the Listing Policy. 4. The Marina Del Rey Back Basins Bacteria TMDL was approved by USEPA on 03/18/2004. 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 150312, Indicator Bacteria	Region 4
Marina del Rey Harbor Beach

LOE ID:

86336

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

1177

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed BW data for Marina del Rey Harbor Beach to determine beneficial use support and results are as follows: 88 of 1177 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 Marina del Rey Harbor Beach was collected at 1 monitoring site [ Marina Del Rey Beach]

Temporal Representation:

Data was collected over the time period 1/1/2005-8/28/2010.

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 150312, Indicator Bacteria	Region 4
Marina del Rey Harbor Beach

LOE ID:

86334

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

1176

Number of Exceedances:

138

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed BW data for Marina del Rey Harbor Beach to determine beneficial use support and results are as follows: 138 of 1176 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 Marina del Rey Harbor Beach was collected at 1 monitoring site [ Marina Del Rey Beach]

Temporal Representation:

Data was collected over the time period 1/1/2005-8/28/2010.

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 150312, Indicator Bacteria	Region 4
Marina del Rey Harbor Beach

LOE ID:

86335

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

1162

Number of Exceedances:

249

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Two hundred forty-nine of the 1162 geomeans exceeded the entercoccus objective.

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 entercoccus 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 Marina Del Rey Beach.

Temporal Representation:

Samples were collected approximately once a day from 2005 to 2010.

Environmental Conditions:

QAPP Information:

The samples were collected for the Beach Watch program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 150312, Indicator Bacteria	Region 4
Marina del Rey Harbor Beach

LOE ID:

86354

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

1163

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Twenty-two of the 1163 geomeans exceeded the fecal coliform objective.

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 Marina Del Rey Beach

Temporal Representation:

Samples were collected approximately once a day from 2005 to 2010.

Environmental Conditions:

QAPP Information:

The samples were collected for the Beach Watch program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 150312, Indicator Bacteria	Region 4
Marina del Rey Harbor Beach

LOE ID:

303087

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

GeoMean

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 LA County MS4 data for Marina del Rey Harbor Beach to determine beneficial use support and the results are as follows: 14 of the 18 samples exceeded the geomean water quality threshold for Enterococcus. This is a six week rolling geomean that is calculated weekly.

Data Reference:

WQ data from the MS4 database 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 where the salinity is 1 ppth or higher 95 percent or more of the time applies a six-week rolling geomean to enterococcus, not to exceed 30 cfu/100mL. (ISWEBE 2018)

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): MdRH-3 (NA).

Temporal Representation:

The samples were collected between the days of 2018-07-02 and 2018-12-31 .

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)

Line of Evidence (LOE) for Decision ID 150312, Indicator Bacteria	Region 4
Marina del Rey Harbor Beach

LOE ID:

86355

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Shellfish Harvesting

Number of Samples:

1177

Number of Exceedances:

517

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed bw data for Marina del Rey Harbor Beach to determine beneficial use support and results are as follows: 517 of 1177 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 Marina del Rey Harbor Beach was collected at 1 monitoring site [ Marina Del Rey Beach]

Temporal Representation:

Data was collected over the time period 1/1/2005-8/28/2010.

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 150312, Indicator Bacteria	Region 4
Marina del Rey Harbor Beach

LOE ID:

86356

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

1177

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed BW data for Marina del Rey Harbor Beach to determine beneficial use support and results are as follows: 52 of 1177 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 Marina del Rey Harbor Beach was collected at 1 monitoring site [ Marina Del Rey Beach]

Temporal Representation:

Data was collected over the time period 1/1/2005-8/28/2010.

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 150312, Indicator Bacteria	Region 4
Marina del Rey Harbor Beach

LOE ID:

86357

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

1163

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Forty-three of the 1163 geomeans exceeded the total coliform objective.

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 total 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 Marina Del Rey Beach.

Temporal Representation:

Samples were collected approximately once a day from 2005 to 2010.

Environmental Conditions:

QAPP Information:

The samples were collected for the Beach Watch program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 150312, Indicator Bacteria	Region 4
Marina del Rey Harbor Beach

LOE ID:

303191

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 LA County MS4 data for Marina del Rey Harbor Beach to determine beneficial use support and the results are as follows: 4 of the 6 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:

WQ data from the MS4 database 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 where the salinity is 1 ppth or higher 95 percent or more of the time 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. (ISWEBE 2018)

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): MdRH-3 (NA).

Temporal Representation:

The samples were collected between the days of 2018-07-02 and 2018-12-31 .

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)

Line of Evidence (LOE) for Decision ID 150312, Indicator Bacteria	Region 4
Marina del Rey Harbor Beach

LOE ID:

3621

Pollutant:

Indicator Bacteria

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):