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

Supporting Information

Regional Board 1 - North Coast Region

Water Body Name: Black Point
Water Body ID: CAC1138503020081029161816
Water Body Type: Coastal & Bay Shoreline
 
DECISION ID
11853
Region 1     
Black Point
 
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: Indicator bacteria (which includes enterococcus, fecal coliform, and total coliform) is being considered for placement on the Section 303(d) list under Section 3.3 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess indicator bacteria. Data assessed for the 2008 Integrated Report include ocean beach bacteria data collected by the Sonoma County Division of Environmental Health in accordance with AB411 (Chapter 765, Statutes of 1997) requirements. In accordance with Section 3.3 of the Listing Policy, a 4% exceedance percentage shall be used to add waters to the List. This equates to no more than 3 exceedances each for enterococcus, fecal coliform, and total coliform single sample values. This also equates to no more than 1 exceedance each for enterococcus, fecal coliform, and total coliform 30-day geomean values. None of the enterococcus, fecal coliform, and total coliform samples (both single samples and geomean values) exceed the objectives. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against adding this water segment-pollutant combination to the Section 303(d) list (i.e., sufficient justification to not 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) Enterococcus, fecal coliform, and total coliform samples do not exceed the objectives more than the 4% allowable frequency identified in Section 3.3 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, North Coast 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 11853, Indicator Bacteria
Region 1     
Black Point
 
LOE ID: 25263
 
Pollutant: Enterococcus
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 74
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: None of the 74 single samples of enterococcus collected at Black Point exceed the objective. Additionally, none of the 16 30-day geomean values exceed the objective. The single sample and geomean values are two different matrices used to analyzed the same data. Samples were collected by the Sonoma County Division of Environmental Health in accordance with AB411 (Chapter 765, Statutes of 1997) requirements. Data is maintained by the State Water Board's Beach Watch program. Data is summarized by the North Coast Regional Water Board (North Coast RWQCB 2007).
Data Reference: North Coast Beach Watch Data. Bacteria data collected by Del Norte County, Humboldt County, Mendocino County Environmental Health Division, Sonoma County Division of Environmental Health, and Marin County in accordance with AB411. Data managed by the State Water Resources Control Board's Beach Watch program at beachwatch.waterboards.ca.gov. Includes data from 2004 to 2006
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Per the Ocean Plan (SWRCB 2005): The following bacterial objectives shall be maintained throughout the water column. The following standard is based on the 30-day geometric mean of the 5 most recent samples from each site: Enterococcus density shall not exceed 35 MPN per 100ml. The following standard is for the single sample maximum: Enterococcus density shall not exceed 104 per 100 ml. *Note: MPN is the most probable number of coliform units.
Objective/Criterion Reference: Water Quality Control Plan Ocean Waters of California. California Ocean Plan 2005. Sacramento, CA: State Water Resources Control Board, California Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected at Black Point.
Temporal Representation: Samples were collected weekly from April through December 2005, and from April to October 2006.
Environmental Conditions: Samples were collected during the dry season. Otherwise, there are no known environmental conditions (e.g., land use practices, fire events, storms, etc.) that are related to these data.
QAPP Information: Samples were collected in accordance with the procedures described in "Environmental Health Policy and Procedure No. 00-1" (Krug 2000).
QAPP Information Reference(s): Environmental Health Policy and Procedure No. 00-1. Subject: Ocean Water Sampling Program Procedures. County of Sonoma Department of Health Services
 
Line of Evidence (LOE) for Decision ID 11853, Indicator Bacteria
Region 1     
Black Point
 
LOE ID: 25261
 
Pollutant: Total Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 74
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: None of the 74 single samples of total coliform collected at Black Point exceed the objective. Additionally, none of the 16 30-day geomean values exceed the objective. The single sample and geomean values are two different matrices used to analyzed the same data. Samples were collected by the Sonoma County Division of Environmental Health in accordance with AB411 (Chapter 765, Statutes of 1997) requirements. Data is maintained by the State Water Board's Beach Watch program. Data is summarized by the North Coast Regional Water Board (North Coast RWQCB 2007).
Data Reference: North Coast Beach Watch Data. Bacteria data collected by Del Norte County, Humboldt County, Mendocino County Environmental Health Division, Sonoma County Division of Environmental Health, and Marin County in accordance with AB411. Data managed by the State Water Resources Control Board's Beach Watch program at beachwatch.waterboards.ca.gov. Includes data from 2004 to 2006
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Per the Ocean Plan (SWRCB 2005): The following bacterial objectives shall be maintained throughout the water column. The following standard is based on the 30-day geometric mean of the five most recent samples from each site: Total coliform density shall not exceed 1,000 MPN per 100 ml. The following standard is for the single sample maximum: (i) Total coliform density shall not exceed 10,000 per 100 ml; and (ii) Total coliform density shall not exceed 1,000 per 100 ml when the fecal coliform/total coliform ratio exceeds 0.1. *Note: MPN is the most probable number of coliform units.
Objective/Criterion Reference: Water Quality Control Plan Ocean Waters of California. California Ocean Plan 2005. Sacramento, CA: State Water Resources Control Board, California Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected at Black Point.
Temporal Representation: Samples were collected weekly from April through December 2005, and from April to October 2006.
Environmental Conditions: Samples were collected during the dry season. Otherwise, there are no known environmental conditions (e.g., land use practices, fire events, storms, etc.) that are related to these data.
QAPP Information: Samples were collected in accordance with the procedures described in "Environmental Health Policy and Procedure No. 00-1" (Krug 2000).
QAPP Information Reference(s): Environmental Health Policy and Procedure No. 00-1. Subject: Ocean Water Sampling Program Procedures. County of Sonoma Department of Health Services
 
Line of Evidence (LOE) for Decision ID 11853, Indicator Bacteria
Region 1     
Black Point
 
LOE ID: 25262
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 74
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: None of the 74 single samples of fecal coliform collected at Black Point exceed the objective. Additionally, none of the 16 30-day geomean values exceed the objective. The single sample and geomean values are two different matrices used to analyzed the same data. Samples were collected by the Sonoma County Division of Environmental Health in accordance with AB411 (Chapter 765, Statutes of 1997) requirements. Data is maintained by the State Water Board's Beach Watch program. Data is summarized by the North Coast Regional Water Board (North Coast RWQCB 2007).
Data Reference: North Coast Beach Watch Data. Bacteria data collected by Del Norte County, Humboldt County, Mendocino County Environmental Health Division, Sonoma County Division of Environmental Health, and Marin County in accordance with AB411. Data managed by the State Water Resources Control Board's Beach Watch program at beachwatch.waterboards.ca.gov. Includes data from 2004 to 2006
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Per the Ocean Plan (SWRCB 2005): The following bacterial objectives shall be maintained throughout the water column. The following standard is based on the 30-day geometric mean of the five most recent samples from each site: Fecal coliform density shall not exceed 200 MPN per 100 ml. The following standard is for the single sample maximum: Fecal coliform density shall not exceed 400 per 100ml. *Note: MPN is the most probable number of coliform units.
Objective/Criterion Reference: Water Quality Control Plan Ocean Waters of California. California Ocean Plan 2005. Sacramento, CA: State Water Resources Control Board, California Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected at Black Point.
Temporal Representation: Samples were collected weekly from April through December 2005, and from April to October 2006.
Environmental Conditions: Samples were collected during the dry season. Otherwise, there are no known environmental conditions (e.g., land use practices, fire events, storms, etc.) that are related to these data.
QAPP Information: Samples were collected in accordance with the procedures described in "Environmental Health Policy and Procedure No. 00-1" (Krug 2000).
QAPP Information Reference(s): Environmental Health Policy and Procedure No. 00-1. Subject: Ocean Water Sampling Program Procedures. County of Sonoma Department of Health Services