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

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name:	Oxnard Beach Park
Water Body ID:	CAC4031100020090226103012
Water Body Type:	Coastal & Bay Shoreline


DECISION ID	150608	Region 4
Oxnard Beach Park

Pollutant:	Indicator Bacteria
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.3 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. 0 of 301 samples exceeded the geometric mean for Enterococcus. 1 of 129 samples exceeded the statistical threshold value for Enterococcus. 0 of 2 samples exceeded the single sample maximum for fecal coliform. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 0 of 301, 1 0f 129 and 0 of 2 samples exceeded the objectives and this does not exceed 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 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:

Line of Evidence (LOE) for Decision ID 150608, Indicator Bacteria	Region 4
Oxnard Beach Park

LOE ID:

302075

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 BeachWatch_Ventura County data for Oxnard Beach Park to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the water quality threshold for Coliform, Fecal. The water quality threshold is based on a Single Sample Maximum (SSM) value that is calculated daily. 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 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): 32000 (32000-Oxnard Beach Park, Ventura).

Temporal Representation:

The samples were collected between the days of 2015-09-15 and 2015-09-15 .

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 150608, Indicator Bacteria	Region 4
Oxnard Beach Park

LOE ID:

302111

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:

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): 33000 (33000-Oxnard Beach Park, Ventura).

Temporal Representation:

The samples were collected between the days of 2015-09-15 and 2015-09-15 .

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 150608, Indicator Bacteria	Region 4
Oxnard Beach Park

LOE ID:

302002

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 Oxnard Beach Park to determine beneficial use support and the results are as follows: 1 of the 65 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:

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): 32000 (32000-Oxnard Beach Park, Ventura).

Temporal Representation:

The samples were collected between the days of 2010-10-05 and 2020-10-13 .

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 150608, Indicator Bacteria	Region 4
Oxnard Beach Park

LOE ID:

301949

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

GeoMean

Beneficial Use:

Water Contact Recreation

Number of Samples:

150

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed BeachWatch_Ventura County data for Oxnard Beach Park to determine beneficial use support and the results are as follows: 0 of the 150 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): 32000 (32000-Oxnard Beach Park, Ventura).

Temporal Representation:

The samples were collected between the days of 2010-10-05 and 2020-10-13 .

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 150608, Indicator Bacteria	Region 4
Oxnard Beach Park

LOE ID:

27885

Pollutant:

Indicator Bacteria

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Other Agencies/Organizations provided monitoring data

Data Used to Assess Water Quality:

0 of 61 samples exceeded the Basin Plan single sample water quality objectives for indicator bacteria in marine water. 0 out of 14 samples exceeded the Basin Plan geometric mean water quality objectives. Water quality samples were taken and analyzed for indicator bacteria consistent with California Code of Regulations Title 17, sections 7958-7961 and related guidance issued by California Department of Public Health .

Data Reference:

County of Ventura coastal beach bacteria monitoring data for AB411.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan bacteria objectives state that to protect water contact recreation in marine waters individual samples shall not exceed the following limits: the total coliform density shall not exceed 10000/100 ml; the fecal coliform density shall not exceed 400/100 ml; the enterococcus density shall not exceed 104/100 ml; and the total coliform density shall not exceed 1,000/100 ml, if the ratio of fecal-to-total coliform exceeds 0.1 as single samples. The bacteria objectives also establish that the geometric means of individual samples shall not exceed the following limits: the total coliform density shall not exceed 1000/100 ml, the fecal coliform density shall not exceed 200/100 ml, and the enterococcus density shall not exceed 35/100 ml, as a geometric mean. The bacteria objectives are found in Attachment A of Regional Board Resolution No. 2001-018.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One Ventura County Environmental Health Division sampling location (VC33000) located south of the drain at Starfish Drive. (Lat: 34.17651, Long: -119.23708).

Temporal Representation:

Grab samples were taken and analyzed on a weekly basis from April 2005 to October 2006 in the summer months of April to October.

Environmental Conditions:

QAPP Information:

Data was collected in compliance with the sampling and testing procedures detailed in the California Department of Public Health related guidance.

QAPP Information Reference(s):

Draft Guidance for Salt Water Beaches. Last Update: April 10, 2006. Initial Draft: November 1997. Division of Drinking Water and Environmental Management, California Department of Health Services

QAPP Information Reference(s):

California Code of Regulations Title 17, sections 7958-7960.

Line of Evidence (LOE) for Decision ID 150608, Indicator Bacteria	Region 4
Oxnard Beach Park

LOE ID:

301936

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

GeoMean

Beneficial Use:

Water Contact Recreation

Number of Samples:

151

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed BeachWatch_Ventura County data for Oxnard Beach Park to determine beneficial use support and the results are as follows: 0 of the 151 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): 33000 (33000-Oxnard Beach Park, Ventura).

Temporal Representation:

The samples were collected between the days of 2010-10-05 and 2020-10-13 .

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 150608, Indicator Bacteria	Region 4
Oxnard Beach Park

LOE ID:

27883

Pollutant:

Indicator Bacteria

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Other Agencies/Organizations provided monitoring data

Data Used to Assess Water Quality:

0 of 30 samples exceeded the Basin Plan single sample water quality objectives for indicator bacteria in marine water. 0 out of 7 samples exceeded the Basin Plan geometric mean water quality objectives. Water quality samples were taken and analyzed for indicator bacteria consistent with California Code of Regulations Title 17, sections 7958-7961 and related guidance issued by California Department of Public Health .

Data Reference:

County of Ventura coastal beach bacteria monitoring data for AB411.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One Ventura County Environmental Health Division sampling location (VC32000) located south of the drain at Falkirk Ave. (Lat: 34.17873, Long: -119.23845).

Temporal Representation:

Grab samples were taken and analyzed on a weekly basis from April 2006 to October 2006 in the summer months of April to October.

Environmental Conditions:

QAPP Information:

Data was collected in compliance with the sampling and testing procedures detailed in the California Department of Public Health related guidance.

QAPP Information Reference(s):

Draft Guidance for Salt Water Beaches. Last Update: April 10, 2006. Initial Draft: November 1997. Division of Drinking Water and Environmental Management, California Department of Health Services

QAPP Information Reference(s):

California Code of Regulations Title 17, sections 7958-7960.

Line of Evidence (LOE) for Decision ID 150608, Indicator Bacteria	Region 4
Oxnard Beach Park

LOE ID:

27882

Pollutant:

Indicator Bacteria

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

137

Number of Exceedances:

Data and Information Type:

Other Agencies/Organizations provided monitoring data

Data Used to Assess Water Quality:

5 of 137 samples exceeded the Basin Plan single sample water quality objectives for indicator bacteria in marine water and 1 out of 33 samples exceeded the geometric mean limits. Water quality samples were taken and analyzed for indicator bacteria consistent with California Code of Regulations Title 17, sections 7958-7961 and related guidance issued by California Department of Public Health .

Data Reference:

County of Ventura coastal beach bacteria monitoring data for AB411.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One Ventura County Environmental Health Division sampling location (VC32000) located south of the drain at Falkirk Ave. (Lat: 34.17873, Long: -119.23845).

Temporal Representation:

Grab samples were taken and analyzed on a weekly basis from January 2003 to October 2005.

Environmental Conditions:

QAPP Information:

Data was collected in compliance with the sampling and testing procedures detailed in the California Department of Public Health related guidance.

QAPP Information Reference(s):

California Code of Regulations Title 17, sections 7958-7960.

QAPP Information Reference(s):

Draft Guidance for Salt Water Beaches. Last Update: April 10, 2006. Initial Draft: November 1997. Division of Drinking Water and Environmental Management, California Department of Health Services

Line of Evidence (LOE) for Decision ID 150608, Indicator Bacteria	Region 4
Oxnard Beach Park

LOE ID:

27884

Pollutant:

Indicator Bacteria

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Other Agencies/Organizations provided monitoring data

Data Used to Assess Water Quality:

0 of 30 samples exceeded the Basin Plan single sample water quality objectives for indicator bacteria in marine water and 0 out of 22 samples exceeded the geometric mean limits. Water quality samples were taken and analyzed for indicator bacteria consistent with California Code of Regulations Title 17, sections 7958-7961 and related guidance issued by California Department of Public Health .

Data Reference:

County of Ventura coastal beach bacteria monitoring data for AB411.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One Ventura County Environmental Health Division sampling location (VC33000) located south of the drain at Starfish Drive. (Lat: 34.17651, Long: -119.23708).

Temporal Representation:

Grab samples were taken and analyzed on a weekly basis from January 2003 to October 2004.

Environmental Conditions:

QAPP Information:

Data was collected in compliance with the sampling and testing procedures detailed in the California Department of Public Health related guidance.

QAPP Information Reference(s):

California Code of Regulations Title 17, sections 7958-7960.

QAPP Information Reference(s):

Draft Guidance for Salt Water Beaches. Last Update: April 10, 2006. Initial Draft: November 1997. Division of Drinking Water and Environmental Management, California Department of Health Services

Line of Evidence (LOE) for Decision ID 150608, Indicator Bacteria	Region 4
Oxnard Beach Park

LOE ID:

302040

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 Oxnard Beach Park to determine beneficial use support and the results are as follows: 0 of the 64 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): 33000 (33000-Oxnard Beach Park, Ventura).

Temporal Representation:

The samples were collected between the days of 2010-10-05 and 2020-10-13 .

Environmental Conditions:

QAPP Information:

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

QAPP Information Reference(s):

QAPP Reference for Beach Watch Program