Final California 2010 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name:	Silverstrand Beach
Water Body ID:	CAC4031100020090226150121
Water Body Type:	Coastal & Bay Shoreline


DECISION ID	16276	Region 4
Silverstrand Beach

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:	This pollutant is being considered for placement on the section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status. Section 3.3 of the Listing Policy states that a 4 % exceedance percentage shall be used when water quality monitoring was conducted between April 01 through October 31 (summer months) only. As such the referenced data set was analyzed in two portions and described in two separate LOEs due to differing sampling data time frames. For summer months samples geometric mean values were calculated but not used due to an insufficient number of values necessary to re-run the binomial test in the Listing Policy for 4 % exceedance. Table 3.2 of the listing policy states that a minimum of 26 samples is required to apply the binomial test. A sample size of fewer than 26 is insufficient to determine with the power and confidence of the Listing Policy if standards are met. 5 lines of evidence are available in the administrative record to assess this pollutant. 20 of the samples exceed the water quality objective. 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 section 303(d) list in the Water Quality Limited Segments category. 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. For year-round samples from station VC38000: 7 of 192 exceeded the single sample updated Basin Plan water quality objective for indicator bacteria (WQO) and 0 of 45 exceeded the geometric mean WQO and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. For year-round samples from station VC39000: 4 of 95 exceeded the single sample WQO and 0 of 22 exceeded the geometric mean WQO and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 5. For summer months samples from station VC39000: 0 of 61 exceeded the single sample WQO and this does not exceed the allowable frequency described in Section 3.3 of the Listing Policy. 0 of 14 exceeded the geometric mean (WQO) and as stated above this sample size is insufficient to determine if standards are met. 6. For year-round samples from station VC40000: 8 of 141 exceeded the single sample WQO and 2 of 33 exceeded the geometric mean WQO and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 7. For summer months samples from station VC40000: 1 of 30 exceeded the single sample WQO and this does not exceed the allowable frequency described in Section 3.3 of the Listing Policy. 0 of 7 exceeded the geometric mean (WQO) and as stated above this sample size is insufficient to determine if standards are met. 8. 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:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 16276, Indicator Bacteria	Region 4
Silverstrand Beach

LOE ID:

27898

Pollutant:

Indicator Bacteria

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

141

Number of Exceedances:

Data and Information Type:

Other Agencies/Organizations provided monitoring data

Data Used to Assess Water Quality:

8 of 141 samples exceeded the Basin Plan single sample water quality objectives for indicator bacteria in marine water and 2 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:

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 (VC40000) located south of the drain at the end of Sawtelle Ave. (Lat: 34.14738, Long: -119.21682).

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):

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

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

Line of Evidence (LOE) for Decision ID 16276, Indicator Bacteria	Region 4
Silverstrand Beach

LOE ID:

27897

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:

A total of 0 out of 61 samples exceeded the Basin Plan limits for single sample exceedances. 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:

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 (VC39000) located south of the drain at the end of Santa Paula Ave. (Lat: 34.15243, Long: -119.2201).

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

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

Line of Evidence (LOE) for Decision ID 16276, Indicator Bacteria	Region 4
Silverstrand Beach

LOE ID:

27899

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:

A total of 1 out of 30 samples exceeded the Basin Plan limits for single sample exceedances. 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 (VC40000) located south of the drain at the end of Sawtelle Ave. (Lat: 34.14738, Long: -119.21682).

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

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

Line of Evidence (LOE) for Decision ID 16276, Indicator Bacteria	Region 4
Silverstrand Beach

LOE ID:

27896

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:

4 of 95 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 (VC39000) located south of the drain at the end of Santa Paula Ave. (Lat: 34.15243, Long: -119.2201).

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):

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

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

Line of Evidence (LOE) for Decision ID 16276, Indicator Bacteria	Region 4
Silverstrand Beach

LOE ID:

27895

Pollutant:

Indicator Bacteria

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

192

Number of Exceedances:

Data and Information Type:

Other Agencies/Organizations provided monitoring data

Data Used to Assess Water Quality:

7 of 192 samples exceeded the Basin Plan single sample water quality objectives for indicator bacteria in marine water and 0 out of 45 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 (VC38000) located south of jetty at the end of San Nicolas Ave. (Lat: 34.15727, Long: -119.22542).

Temporal Representation:

Grab samples were taken and analyzed on a weekly basis from January 2003 to February 2007.

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

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