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

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name:	Manhattan Beach
Water Body ID:	CAX4051200019990923092303
Water Body Type:	Coastal & Bay Shoreline


DECISION ID	150310	Region 4
Manhattan Beach

Pollutant:	Indicator Bacteria
Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Delist from 303(d) list (being addressed by USEPA approved TMDL)(2018)
Revision Status	Revised
Sources:	See TMDL documentation
TMDL Name:	Santa Monica Bay Beach Closures/Coliform/Bacteria Indicators (48)
TMDL Project Code:	392
Date TMDL Approved by USEPA:	06/19/2003
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 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of 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. 44 of 78 samples exceeded the geometric mean for Enterococcus, 23 of 64 samples exceeded the statistical threshold value for Enterococcus, and 9 of 39 samples exceeded the geometric mean for fecal coliform and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

86318

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

770

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Zero of the 770 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 27th Street extended, 40th Street extended and Manhattan Beach Pier.

Temporal Representation:

Samples were collected approximately once a week 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 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

3605

Pollutant:

Indicator Bacteria

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Public health monitoring data was collected by two local agencies from 2000-2005 and compliance monitoring for the Santa Monica Bay Beaches Bacteria TMDL collected from November 2004 to September 2005. The AB 411 exceedance frequency was exceeded 6 out of the 6 years (Heal the Bay, 2006).

Data Reference:

Placeholder reference 2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Site-specific AB 411 Exceedance Frequency (April- October) per Santa Monica Bay Beaches Bacteria TMDL.

Objective/Criterion Reference:

Placeholder reference 2006 303(d)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Manhattan State Beach at 40th Street, Manhattan Beach- projection of 27th Street, Manhattan Beach Pier 50-yards south.

Temporal Representation:

Samples were collected between 2000 and 2005.

Environmental Conditions:

QAPP Information:

Data were collected by Los Angeles County Sanitation Department and Los Angeles County Department of Health Services.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

86319

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Shellfish Harvesting

Number of Samples:

946

Number of Exceedances:

127

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed bw data for Manhattan Beach to determine beneficial use support and results are as follows: 127 of 946 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 Manhattan Beach was collected at 3 monitoring sites [ 27th Street extended, 40th Street extended, Manhattan Beach Pier]

Temporal Representation:

Data was collected over the time period 1/1/2005-8/24/2010.

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 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

86320

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

946

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed BW data for Manhattan Beach to determine beneficial use support and results are as follows: 22 of 946 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 Manhattan Beach was collected at 3 monitoring sites [ 27th Street extended, 40th Street extended, Manhattan Beach Pier]

Temporal Representation:

Data was collected over the time period 1/1/2005-8/24/2010.

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 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

86321

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

869

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Six of the 869 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 27th Street extended, 40th Street extended, and Manhattan Beach Pier.

Temporal Representation:

Samples were collected approximately once a week 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 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

302166

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 SMBBB Coordinated Shoreline Monitoring Program data for Manhattan Beach to determine beneficial use support and the results are as follows: 0 of the 1 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 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 in ocean waters applies a six-week rolling geomean to enterococcus, not to exceed 30 cfu/100mL. (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): SMB-5-3 (SMB-5-3).

Temporal Representation:

The samples were collected between the days of 2015-08-03 and 2016-03-21 .

Environmental Conditions:

QAPP Information:

The technical Steering committee co-chairs city and county of los angeles co-chairs city and county of los angeles. 2004. SANTA MONICA BAY BEACHES BACTERIAL TMDLs COORDINATED SHORELINE MONITORING PLAN.

QAPP Information Reference(s):

SANTA MONICA BAY BEACHES BACTERIAL TMDLs COORDINATED SHORELINE MONITORING PLAN

Line of Evidence (LOE) for Decision ID 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

302138

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 SMBBB Coordinated Shoreline Monitoring Program data for Manhattan Beach to determine beneficial use support and the results are as follows: 27 of the 46 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 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 in ocean waters applies a six-week rolling geomean to enterococcus, not to exceed 30 cfu/100mL. (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): SMB-5-2 (SMB-5-2).

Temporal Representation:

The samples were collected between the days of 2015-07-01 and 2016-06-23 .

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

SANTA MONICA BAY BEACHES BACTERIAL TMDLs COORDINATED SHORELINE MONITORING PLAN

Line of Evidence (LOE) for Decision ID 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

303099

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 Manhattan Beach to determine beneficial use support and the results are as follows: 3 of the 14 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 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): SMB-5-3 (SMB-5-3).

Temporal Representation:

The samples were collected between the days of 2016-08-20 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 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

302176

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 SMBBB Coordinated Shoreline Monitoring Program data for Manhattan Beach to determine beneficial use support and the results are as follows: 7 of the 12 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 California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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): SMB-5-2 (SMB-5-2).

Temporal Representation:

The samples were collected between the days of 2015-07-01 and 2016-06-23 .

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

SANTA MONICA BAY BEACHES BACTERIAL TMDLs COORDINATED SHORELINE MONITORING PLAN

Line of Evidence (LOE) for Decision ID 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

303001

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 Manhattan Beach to determine beneficial use support and the results are as follows: 4 of the 6 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 in ocean waters applies a six-week rolling geomean to enterococcus, not to exceed 30 cfu/100mL. (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): SMB-5-3 (SMB-5-3).

Temporal Representation:

The samples were collected between the days of 2016-08-20 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 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

302170

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 SMBBB Coordinated Shoreline Monitoring Program data for Manhattan Beach to determine beneficial use support and the results are as follows: 1 of the 8 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 California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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): SMB-5-3 (SMB-5-3).

Temporal Representation:

The samples were collected between the days of 2015-08-03 and 2016-03-21 .

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

SANTA MONICA BAY BEACHES BACTERIAL TMDLs COORDINATED SHORELINE MONITORING PLAN

Line of Evidence (LOE) for Decision ID 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

302999

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 Manhattan Beach to determine beneficial use support and the results are as follows: 13 of the 25 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 in ocean waters applies a six-week rolling geomean to enterococcus, not to exceed 30 cfu/100mL. (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): SMB-5-2 (SMB-5-2).

Temporal Representation:

The samples were collected between the days of 2016-01-20 and 2018-12-28 .

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 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

303135

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 Manhattan Beach to determine beneficial use support and the results are as follows: 12 of the 30 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:

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): SMB-5-2 (SMB-5-2).

Temporal Representation:

The samples were collected between the days of 2016-01-20 and 2018-12-28 .

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 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

303058

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 LA County MS4 data for Manhattan Beach to determine beneficial use support and the results are as follows: 14 of the 53 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:

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 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): SMB-5-2 (SMB-5-2).

Temporal Representation:

The samples were collected between the days of 2016-01-20 and 2018-12-21 .

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 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

302985

Pollutant:

Fecal Coliform

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 Manhattan Beach to determine beneficial use support and the results are as follows: 4 of the 8 samples exceeded the water quality threshold for Coliform, Fecal. The water quality threshold is based on a 30-Day rolling geomean.

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 in ocean waters applies a 30 day geometric mean of fecal coliform based on the five most recent samples at each site, not to exceed 200 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): SMB-5-2 (SMB-5-2).

Temporal Representation:

The samples were collected between the days of 2016-01-20 and 2018-12-21 .

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 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

302156

Pollutant:

Fecal Coliform

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 SMBBB Coordinated Shoreline Monitoring Program data for Manhattan Beach to determine beneficial use support and the results are as follows: 0 of the 5 samples exceeded the water quality threshold for Coliform, Fecal. The water quality threshold is based on a 30-Day rolling geomean.

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:

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): SMB-5-3 (SMB-5-3).

Temporal Representation:

The samples were collected between the days of 2015-07-13 and 2016-06-20 .

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

SANTA MONICA BAY BEACHES BACTERIAL TMDLs COORDINATED SHORELINE MONITORING PLAN

Line of Evidence (LOE) for Decision ID 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

302148

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 SMBBB Coordinated Shoreline Monitoring Program data for Manhattan Beach to determine beneficial use support and the results are as follows: 10 of the 60 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:

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 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): SMB-5-2 (SMB-5-2).

Temporal Representation:

The samples were collected between the days of 2015-07-02 and 2016-06-27 .

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

SANTA MONICA BAY BEACHES BACTERIAL TMDLs COORDINATED SHORELINE MONITORING PLAN

Line of Evidence (LOE) for Decision ID 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

302167

Pollutant:

Fecal Coliform

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 SMBBB Coordinated Shoreline Monitoring Program data for Manhattan Beach to determine beneficial use support and the results are as follows: 5 of the 26 samples exceeded the water quality threshold for Coliform, Fecal. The water quality threshold is based on a 30-Day rolling geomean.

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:

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): SMB-5-2 (SMB-5-2).

Temporal Representation:

The samples were collected between the days of 2015-07-02 and 2016-06-27 .

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

SANTA MONICA BAY BEACHES BACTERIAL TMDLs COORDINATED SHORELINE MONITORING PLAN

Line of Evidence (LOE) for Decision ID 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

302169

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 SMBBB Coordinated Shoreline Monitoring Program data for Manhattan Beach to determine beneficial use support and the results are as follows: 0 of the 30 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:

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 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): SMB-5-3 (SMB-5-3).

Temporal Representation:

The samples were collected between the days of 2015-07-13 and 2016-06-20 .

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

SANTA MONICA BAY BEACHES BACTERIAL TMDLs COORDINATED SHORELINE MONITORING PLAN

Line of Evidence (LOE) for Decision ID 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

303057

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 LA County MS4 data for Manhattan Beach to determine beneficial use support and the results are as follows: 2 of the 49 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:

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 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): SMB-5-3 (SMB-5-3).

Temporal Representation:

The samples were collected between the days of 2016-01-20 and 2018-12-20 .

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 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

86316

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

861

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Seventy of the 861 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 27th Street extended, 40th Street extended and Manhattan Beach Pier.

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 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

86308

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

944

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed BW data for Manhattan Beach to determine beneficial use support and results are as follows: 66 of 944 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 Manhattan Beach was collected at 3 monitoring sites [ 27th Street extended, 40th Street extended, Manhattan Beach Pier]

Temporal Representation:

Data was collected over the time period 1/1/2005-8/24/2010.

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 150310, Indicator Bacteria	Region 4
Manhattan Beach

LOE ID:

86317

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

838

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed BW data for Manhattan Beach to determine beneficial use support and results are as follows: 18 of 838 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 Manhattan Beach was collected at 3 monitoring sites [ 27th Street extended, 40th Street extended, Manhattan Beach Pier]

Temporal Representation:

Data was collected over the time period 1/1/2005-8/24/2010.

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):