Final California 2020 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
75335
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)(2016)
Revision Status Original
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.
Four lines of evidence are available in the administrative record to assess this pollutant.
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
 
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.
 
 
Line of Evidence (LOE) for Decision ID 75335, 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: 30
Number of Exceedances: 0
 
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: 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 (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 75335, 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: 5
 
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: 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 (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 75335, 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: 94
Number of Exceedances: 2
 
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: 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 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 75335, 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: 61
Number of Exceedances: 0
 
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.