Draft 2008 California 303(d)/305(b) Integrated Report

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name: Rincon Beach
Water Body ID: CAX4010001020020131134348
Water Body Type: Coastal & Bay Shoreline
 
DECISION ID
4148
 
Pollutant: Indicator Bacteria
Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)(2006)
Revision Status Revised
Sources: Nonpoint Source | Point Source
Expected TMDL Completion Date: 2015
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: This pollutant is being considered for removal from the section 303(d) list under section 4.3 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Nine lines of evidence are available in the administrative record to assess this pollutant.

A 19% exceedance percentage was used for water quality monitoring conducted between April 01 through October 31 (summer months) only. Section 4.3 of the Listing Policy does not describe the use of a more stringent exceedance percentage for summer only beach bacteria monitoring, though one is inferred. As such the referenced data set was analyzed in two portions and described in two separate LOEs due to differing sampling time frames.

Rincon Beach was not addressed in the Santa Monica Bay Bacteria TMDLs or listed in Basin Plan Amendments 2002-004 and 2002-022. As such, information from line of evidence 3509 will be disregarded and will not be considered in this decision.

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 on the section 303(d) list in the Water Quality Limited Segment.

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. 47 of 257 samples, sampled year-round, from monitoring station VC1000 exceeded the updated Basin Plan single sample water quality objectives, 12 of 32 samples exceeded the geometric mean water quality objectives for indicator bacteria, and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy for single samples and geometric means.
4. Seven of 35 samples from monitoring station VC1000 exceeded the Basin Plan single sample water quality objectives for indicator bacteria, and this exceeds the allowable frequency for monitoring in the summer months only. Five of seven samples exceeded the geometric mean water quality objectives and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are met. A minimum of 26 samples in needed for application of table 4.2, utilizing a 19% exceedance percentage.
5. 34 of 302 samples, sampled year-round, from monitoring station VC1050 exceeded the updated Basin Plan single sample water quality objectives, six of 45 samples exceeded the geometric mean water quality objectives for indicator bacteria, and this does not exceed the allowable frequency listed in Table 4.2 of the Listing Policy.
6. 21 of 197 samples, sampled year-round, from monitoring station VC1100 exceeded the updated Basin Plan single sample water quality objectives, two of 22 samples exceeded the geometric mean water quality objectives for indicator bacteria, and this does not exceed the allowable frequency listed in Table 4.2.
7. Four of 65 samples from monitoring station VC1100 exceeded the Basin Plan single sample water quality objectives for indicator bacteria, and this does not exceed the allowable frequency for monitoring in the summer months only. One of 14 samples exceeded the geometric mean water quality objectives and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are met. A minimum of 26 samples in needed for application of table 4.2, utilizing a 19% exceedance percentage.
8. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.
 
RWQCB Board Decision / Staff 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.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 4148
 
LOE ID: 28186
 
Pollutant: Indicator Bacteria
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 65
Number of Exceedances: 4
 
Data and Information Type: Other Agencies/Organizations provided monitoring data
Data Used to Assess Water Quality: Four out of 65 samples exceeded the Basin Plan single sample water quality objectives for indicator bacteria in marine water and one 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.
 
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
  Basin Plan Amendments to the Water Quality Control Plan Los Angeles Region R4 Basin Plan as of 02/02/2009
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The Ventura County Environmental Health Division conducted sampling at Rincon Beach at beach monitoring station VC1100, located at the end of footpath to the beach (Lat: 34.37537, Long: -119.47304).
Temporal Representation: Grab samples were taken and analyzed on a weekly basis from April 2005 to October 2006.
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.
 
LOE ID: 28185
 
Pollutant: Indicator Bacteria
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 96
Number of Exceedances: 6
 
Data and Information Type: Other Agencies/Organizations provided monitoring data
Data Used to Assess Water Quality: Six out of 96 samples exceeded the Basin Plan single sample water quality objectives for indicator bacteria in marine water and two out of 22 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.
 
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
  Basin Plan Amendments to the Water Quality Control Plan Los Angeles Region R4 Basin Plan as of 02/02/2009
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The Ventura County Environmental Health Division conducted sampling at Rincon Beach at beach monitoring station VC1100, located at the end of footpath to the beach (Lat: 34.37537, Long: -119.47304).
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.
 
LOE ID: 28184
 
Pollutant: Indicator Bacteria
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 198
Number of Exceedances: 11
 
Data and Information Type: Other Agencies/Organizations provided monitoring data
Data Used to Assess Water Quality: 11 out of 198 samples exceeded the Basin Plan single sample water quality objectives for indicator bacteria in marine water and six out of 45 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.
 
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
  Basin Plan Amendments to the Water Quality Control Plan Los Angeles Region R4 Basin Plan as of 02/02/2009
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The Ventura County Environmental Health Division conducted sampling at Rincon Beach at beach monitoring station VC1050, located at the flagpole 100 yards south of the mouth of Rincon Creek (Lat: 34.37389, Long: -119.47494).
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.
 
LOE ID: 28183
 
Pollutant: Indicator Bacteria
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 35
Number of Exceedances: 7
 
Data and Information Type: Other Agencies/Organizations provided monitoring data
Data Used to Assess Water Quality: Seven out of 35 samples exceeded the Basin Plan single sample water quality objectives for indicator bacteria in marine water and five out of seven 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.
 
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
  Basin Plan Amendments to the Water Quality Control Plan Los Angeles Region R4 Basin Plan as of 02/02/2009
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The Ventura County Environmental Health Division conducted sampling at Rincon Beach at beach monitoring station VC1000, located 25 yards south of the mouth of Rincon Creek (Lat: 34.37328, Long: -119.47652).
Temporal Representation: Grab samples were taken and analyzed on a weekly basis from April 2006 to October 2006.
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.
 
LOE ID: 3509
 
Pollutant: Indicator Bacteria
LOE Subgroup: Narrative Description Data
Matrix: Not Specified
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: A TMDL and implementation plan has been approved for this water segment-pollutant combination. The Santa Monica Bay Bacteria Dry Weather TMDL was approved by RWQCB on January 24, 2002 and subsequently approved by USEPA. The Santa Monica Bay Bacteria Wet Weather TMDL was approved by RWQCB on December 12, 2002 and approved by USEPA on June 19, 2003.
Data Reference: Placeholder reference 2006 303(d)
 
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):
 
LOE ID: 3512
 
Pollutant: Indicator Bacteria
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 104
Number of Exceedances: 23
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: 104 samples, 23 samples exceeding (SWRCB, 2003).
Data Reference: Placeholder reference 2006 303(d)
 
Water Quality Objective/Criterion: 17 CCR 7958 (in part): The minimum protective bacteriological standards for waters adjacent to public beaches and public water-contact sports areas shall be as follows:
(1) Based on a single sample, the density of bacteria in water from each sampling station at a public beach or public water contact sports area shall not exceed:
(A) 1,000 total coliform bacteria per 100 milliliters, if the ratio of fecal/total coliform bacteria exceeds 0.1; or
(B) 10,000 total coliform bacteria per 100 milliliters; or
(C) 400 fecal coliform bacteria per 100 milliliters; or
(D) 104 enterococcus bacteria per 100 milliliters.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: 1 station: VC(1050). This station represents the beach 50 yards on either
side of the sampling point. Sampled collected 150 yards south of the creek's mouth.
Temporal Representation: Data collected in 1999, 2000, and 2001.
Environmental Conditions:
QAPP Information: County Health Department.
QAPP Information Reference(s):
 
LOE ID: 3511
 
Pollutant: Indicator Bacteria
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 101
Number of Exceedances: 15
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Data used to assess water quality 101 samples, 15 samples exceeding (SWRCB, 2003).
Data Reference: Placeholder reference 2006 303(d)
 
Water Quality Objective/Criterion: 17 CCR 7958 (in part): The minimum protective bacteriological standards for waters adjacent to public beaches and public water-contact sports areas shall be as follows:
(1) Based on a single sample, the density of bacteria in water from each sampling station at a public beach or public water contact sports area shall not exceed:
(A) 1,000 total coliform bacteria per 100 milliliters, if the ratio of fecal/total coliform bacteria exceeds 0.1; or
(B) 10,000 total coliform bacteria per 100 milliliters; or
(C) 400 fecal coliform bacteria per 100 milliliters; or
(D) 104 enterococcus bacteria per 100 milliliters.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: 1 station: VC(1100). This station represents the beach 50 yards on either
side of the sampling point. Samples collected at the end of the footpath.
Temporal Representation: Data collected in 1999, 2000, and 2001.
Environmental Conditions:
QAPP Information: County Health Department.
QAPP Information Reference(s):
 
LOE ID: 3510
 
Pollutant: Indicator Bacteria
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 107
Number of Exceedances: 26
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: 107 samples, 26 samples exceeding (SWRCB, 2003).
Data Reference: Placeholder reference 2006 303(d)
 
Water Quality Objective/Criterion: 17 CCR 7958 (in part): The minimum protective bacteriological standards for waters adjacent to public beaches and public water-contact sports areas shall be as follows:
(1) Based on a single sample, the density of bacteria in water from each sampling station at a public beach or public water contact sports area shall not exceed:
(A) 1,000 total coliform bacteria per 100 milliliters, if the ratio of fecal/total coliform bacteria exceeds 0.1; or
(B) 10,000 total coliform bacteria per 100 milliliters; or
(C) 400 fecal coliform bacteria per 100 milliliters; or
(D) 104 enterococcus bacteria per 100 milliliters.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: 1 station: VC(1000). This station represents the beach 50 yards on either
side of the sampling point. Sample were collected 50 yards from the mouth of the creek.
Temporal Representation: Data collected in 1999, 2000, and 2001.
Environmental Conditions:
QAPP Information: County Health Department.
QAPP Information Reference(s):
 
LOE ID: 28182
 
Pollutant: Indicator Bacteria
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 150
Number of Exceedances: 21
 
Data and Information Type: Other Agencies/Organizations provided monitoring data
Data Used to Assess Water Quality: 21 out of 150 samples exceeded the Basin Plan single sample water quality objectives for indicator bacteria in marine water and 12 out of 32 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.
 
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
  Basin Plan Amendments to the Water Quality Control Plan Los Angeles Region R4 Basin Plan as of 02/02/2009
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The Ventura County Environmental Health Division conducted sampling at Rincon Beach at beach monitoring station VC1000, located 25 yards south of the mouth of Rincon Creek (Lat: 34.37328, Long: -119.47652).
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.