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

Supporting Information

Regional Board 9 - San Diego Region

Water Body Name: Mission Bay Shoreline, at Bahia Point
Water Body ID: CAC9075100020090422203910
Water Body Type: Coastal & Bay Shoreline
 
DECISION ID
16635
 
Pollutant: Fecal Coliform
Final Listing Decision: Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Reason for Delisting: State determines water quality standard is being met
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: In 2006, 'Mission Bay Shoreline' was listed for Indicator Bacteria. For 2008, the 2006 Mission Bay Shoreline segment has been split into smaller segments and each represents an area near the sampling location of the data being assessed. 'Mission Bay Shoreline, at Bahia Point' is one of the sampling locations for Mission Bay Shoreline, and is considered to be part of the original listing.

For this 2008 assessment, the Regional Board has chosen to replace the 'indicator bacteria' listing with separate assessments of the specific indicator bacteria, such as total coliform, fecal coliform, and enterococcus, for removal or non-removal from the 303(d) list.

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.

Four lines of evidence are available in the administrative record to assess this pollutant. Forty three of samples exceeded the water quality objective for fecal coliform.

In LOE 28687, the Regional Board calculated exceedances for samples taken only during storm events. This information was not used in determining listing decisions, but is of interest to the Regional Board and has been included as additional anecdotal information.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for removing this water segment-pollutant combination from the 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. Forty-three of 358 samples exceeded the fecal coliform water quality objective and this does not exceed the allowable frequency listed in Table 4.2 of the Listing Policy.
4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be removed from the section 303(d) list because applicable water quality standards for the pollutant are not being exceeded.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 16635
 
LOE ID: 30338
 
Pollutant: Indicator Bacteria
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 2933
Number of Exceedances: 959
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Below is a copy of the 2006 LOE for the data supporting the listing of Mission Bay Shoreline:

Available data indicate sufficient exceedances of bacterial indicator objectives. There were 576 out of 3662 samples exceeding the single sample maximum for enterococci, 959 out of 2933 exceedances of the geomean enterococci, and 333 out samples exceeding the single sample maximum for fecal coliform (USEPA, 2007).
Data Reference: Placeholder reference 2006 303(d)
 
Water Quality Objective/Criterion: Title 17 C.C.R. Section 7958 states: 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.

Based on the mean of the logarithms of the results of at least five weekly samples during any 30-day sampling period, the density of bacteria in water from any sampling station at a public beach or public water contact sports area, shall not exceed:
(A) 1,000 total coliform bacteria per 100 milliliters; or
(B) 200 fecal coliform bacteria per 100 milliliters; or
(C) 35 enterococcus bacteria per 100 milliliters (DHS, 1999).
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: In 2006, data from sampling sites along the Mission Bay shoreline were aggregated for the assessment. For 2008, the 2006 Mission Bay Shoreline segment has been split into smaller segments and each represents an area near the sampling location of the data being assessed. 'Mission Bay Shoreline, at Bahia Point ' is one of the sampling locations for Mission Bay Shoreline and is considered to be part of the original listing
Temporal Representation: From 03/21/2000-10/30/2005.
Environmental Conditions:
QAPP Information: Data record: 2000-2005, San Diego County Health Dept.
QAPP Information Reference(s):
 
LOE ID: 28687
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 14
Number of Exceedances: 6
 
Data and Information Type: PWS pathogen monitoring (ambient water)
Data Used to Assess Water Quality: Beach monitoring data was collected by the County of San Diego from January 1999 through December 2007. A total of 358 single samples were collected with 14 samples correlated with a storm event. Six of the 14 samples exceeded the single sample water quality objective. This information will not be used in determining a listing decision, but is of interest to the Regional Board and has been included here as additional anecdotal information.
Data Reference: National Weather Service Forecast Office, San Diego, California, Chronological Regional Temperature and Precipitation Listings by Station
  Department of Environmental Health, Ocean & Bay Recreational Water Quality Program, 2007. AB 411 monitoring data 1999 to 2007.
 
Water Quality Objective/Criterion: Geomean; Fecal coliform density shall not exceed 200 per 100 ml;

Single Sample Maximum; Fecal coliform density shall not exceed 400 per 100 ml (SWRCB, 2005).

Comparisons are also made only for days with matching bacteria and storm event data. A storm event was defined as 0.2 inches of rainfall within a 72 hour period.
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 from Bahia Point, San Diego, California. Station identification number is MB-160.
Temporal Representation: Samples were collected from January 1999 through December 2007.
Environmental Conditions:
QAPP Information: Quality control for the bacteria analysis portion was conducted in accordance with the County of San Diego, Department Public Health Laboratory Quality Assurance Manual.
QAPP Information Reference(s): County of Orange. Quality Assurance/Quality Control Manual, February 2004.
  County of San Diego, 2006. Department Public Health Laboratory, Quality Assurance Manual, December 2006.
 
LOE ID: 28686
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 70
Number of Exceedances: 4
 
Data and Information Type: PWS pathogen monitoring (ambient water)
Data Used to Assess Water Quality: Beach monitoring data was collected by the County of San Diego from January 1999 through October 2007. A total of 358 single samples were collected and 70 geomeans calculated. Four of the 70 geomeans exceeded the geomean water quality objective.
Data Reference: Department of Environmental Health, Ocean & Bay Recreational Water Quality Program, 2007. AB 411 monitoring data 1999 to 2007.
 
Water Quality Objective/Criterion: Geomean; Fecal coliform density shall not exceed 200 per 100 ml;

Single Sample Maximum; Fecal coliform density shall not exceed 400 per 100 ml (SWRCB, 2005).
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 from Bahia Point, San Diego, California. Station identification number is MB-160.
Temporal Representation: Samples were collected from January 1999 through October 2007.
Environmental Conditions:
QAPP Information: Quality control for the bacteria analysis portion was conducted in accordance with the County of San Diego, Department Public Health Laboratory Quality Assurance Manual.
QAPP Information Reference(s): County of San Diego, 2006. Department Public Health Laboratory, Quality Assurance Manual, December 2006.
 
LOE ID: 28682
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 358
Number of Exceedances: 43
 
Data and Information Type: PWS pathogen monitoring (ambient water)
Data Used to Assess Water Quality: Beach monitoring data was collected by the County of San Diego from January 1999 through October 2007. A total of 358 single samples were collected with 43 samples exceeding the single sample water quality objective.
Data Reference: Department of Environmental Health, Ocean & Bay Recreational Water Quality Program, 2007. AB 411 monitoring data 1999 to 2007.
 
Water Quality Objective/Criterion: Geomean; Fecal coliform density shall not exceed 200 per 100 ml;

Single Sample Maximum; Fecal coliform density shall not exceed 400 per 100 ml (SWRCB, 2005).
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 from Bahia Point, San Diego, California. Station identification number is MB-160.
Temporal Representation: Samples were collected from January 1999 through October 2007.
Environmental Conditions:
QAPP Information: Quality control for the bacteria analysis portion was conducted in accordance with the County of San Diego, Department Public Health Laboratory Quality Assurance Manual.
QAPP Information Reference(s): County of San Diego, 2006. Department Public Health Laboratory, Quality Assurance Manual, December 2006.
 
LOE ID: 30107
 
Pollutant: Indicator Bacteria
LOE Subgroup: Health Advisories
Matrix: -N/A
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 2555
Number of Exceedances: 128
 
Data and Information Type: PWS pathogen monitoring (ambient water)
Data Used to Assess Water Quality: For the period from January 2001 to December 2007, there were 128 beach advisory days for this location. When a bacteriological sample exceeds water quality standards, signs are posted indicating that waters have exceeded public health standards.

Data and information on the number of beach posting were summarized by the County of San Diego in their annual San Diego County Beach Closure and Advisory Reports. The reporting period was from January 2001 to December 2007. Data used was the number of days the beach was posted with an Advisory when the ocean or bay failed to meet the bacteriological standards.
Data Reference: County of Orange. March 2007. Annual Ocean and Bay Water Quality Report, 2006.
  Department of Environmental Health, Land and Water Quality Division. San Diego County Beach Closure and Advisory Report.
 
Water Quality Objective/Criterion: California Code of Regulations. Title 17, Section 7960.

(a) When a public beach or public water-contact sports area fails to meet any of the standards as set forth in Section 7957 or 7958 above, the local health officer or the Department, after taking into consideration the causes therefor, may at his or its discretion close, post with warning signs, or otherwise restrict use of said public beach or public water-contact sports area, until such time as corrective action has been taken and the standards as set forth in 7957 and 7958 above are met.
Objective/Criterion Reference: California Code of Regulations, Title 17, Section 7960.
 
Evaluation Guideline:
Guideline Reference: Water Quality Control Plan Ocean Waters of California. California Ocean Plan 2005. Sacramento, CA: State Water Resources Control Board, California Environmental Protection Agency
 
Spatial Representation: Bacteriological monitoring samples were collected at Bahia Point in Mission Bay.
Temporal Representation: The beach posting covers the time frame of January 2001 -December 2007.
Environmental Conditions:
QAPP Information: Quality control for the bacteria analysis portion was conducted in accordance with the County of San Diego, Department Public Health Laboratory Quality Assurance Manual.
QAPP Information Reference(s): County of San Diego, 2006. Department Public Health Laboratory, Quality Assurance Manual, December 2006.
 
DECISION ID
16634
 
Pollutant: Enterococcus
Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Unknown Nonpoint Source | Unknown Point Source | Urban Runoff/Storm Sewers
Expected TMDL Completion Date: 2019
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: In 2006, 'Mission Bay Shoreline' was listed for Indicator Bacteria. For 2008, the 2006 Mission Bay Shoreline segment has been split into smaller segments and each represents an area near the sampling location of the data being assessed. 'Mission Bay Shoreline, at Bahia Point' is one of the sampling locations for Mission Bay Shoreline, and is considered to be part of the original listing.

For this 2008 assessment, the Regional Board has chosen to replace the 'indicator bacteria' listing with separate assessments of the specific indicator bacteria, such as total coliform, fecal coliform, and enterococcus, for removal or non-removal from the 303(d) list.

This pollutant is being considered for removal from the section 303(d) list under section 4.2 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status.

Four lines of evidence are available in the administrative record to assess this pollutant. Eighty-seven of 493 samples exceed the Basin Plan water quality objective for Enterococcus.

In LOE 28670, the Regional Board calculated exceedances for samples taken only during storm events. This information was not used in determining listing decisions, but is of interest to the Regional Board and has been included as additional anecdotal information.

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 from the 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. Eighty-seven of 493 samples exceed the Basin Plan water quality objective for Enterococcus, and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy.
4. 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 16634
 
LOE ID: 28670
 
Pollutant: Enterococcus
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 15
Number of Exceedances: 7
 
Data and Information Type: PWS pathogen monitoring (ambient water)
Data Used to Assess Water Quality: Beach monitoring data was collected by the County of San Diego from January 1999 through December 2007. A total of 399 single samples were collected with 15 samples correlated with a storm event. Seven of the 15 samples exceeded the single sample water quality objective. This information will not be used in determining a listing decision, but is of interest to the Regional Board and has been included here as additional anecdotal information.
Data Reference: National Weather Service Forecast Office, San Diego, California, Chronological Regional Temperature and Precipitation Listings by Station
  Department of Environmental Health, Ocean & Bay Recreational Water Quality Program, 2007. AB 411 monitoring data 1999 to 2007.
 
Water Quality Objective/Criterion: Geomean: Enterococcus density shall not exceed 35 per 100 ml.

Single Sample Maximum: Enterococcus density shall not exceed 104 per 100 ml (SWRCB, 2005).
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 from Bahia Point, San Diego, California. Station identification number is MB-160.
Temporal Representation: Samples were collected from January 1999 through October 2007.
Environmental Conditions: Comparisons were made for all data and data associated with storm events. A storm event was defined as 0.2 inches of rainfall within a 72 hour period.

Analyzing only storm water bacteria data is important because the majority of beach monitoring data covers the months of April through October. The data may not capture the full impacts of seasonal storm events and high bacteria levels due to storm water runoff because much of the wet season for Southern California occurs in November through March.
QAPP Information: Quality control for the bacteria analysis portion was conducted in accordance with the County of San Diego, Department Public Health Laboratory Quality Assurance Manual.
QAPP Information Reference(s): County of San Diego, 2006. Department Public Health Laboratory, Quality Assurance Manual, December 2006.
 
LOE ID: 30338
 
Pollutant: Indicator Bacteria
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 2933
Number of Exceedances: 959
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Below is a copy of the 2006 LOE for the data supporting the listing of Mission Bay Shoreline:

Available data indicate sufficient exceedances of bacterial indicator objectives. There were 576 out of 3662 samples exceeding the single sample maximum for enterococci, 959 out of 2933 exceedances of the geomean enterococci, and 333 out samples exceeding the single sample maximum for fecal coliform (USEPA, 2007).
Data Reference: Placeholder reference 2006 303(d)
 
Water Quality Objective/Criterion: Title 17 C.C.R. Section 7958 states: 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.

Based on the mean of the logarithms of the results of at least five weekly samples during any 30-day sampling period, the density of bacteria in water from any sampling station at a public beach or public water contact sports area, shall not exceed:
(A) 1,000 total coliform bacteria per 100 milliliters; or
(B) 200 fecal coliform bacteria per 100 milliliters; or
(C) 35 enterococcus bacteria per 100 milliliters (DHS, 1999).
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: In 2006, data from sampling sites along the Mission Bay shoreline were aggregated for the assessment. For 2008, the 2006 Mission Bay Shoreline segment has been split into smaller segments and each represents an area near the sampling location of the data being assessed. 'Mission Bay Shoreline, at Bahia Point ' is one of the sampling locations for Mission Bay Shoreline and is considered to be part of the original listing
Temporal Representation: From 03/21/2000-10/30/2005.
Environmental Conditions:
QAPP Information: Data record: 2000-2005, San Diego County Health Dept.
QAPP Information Reference(s):
 
LOE ID: 30107
 
Pollutant: Indicator Bacteria
LOE Subgroup: Health Advisories
Matrix: -N/A
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 2555
Number of Exceedances: 128
 
Data and Information Type: PWS pathogen monitoring (ambient water)
Data Used to Assess Water Quality: For the period from January 2001 to December 2007, there were 128 beach advisory days for this location. When a bacteriological sample exceeds water quality standards, signs are posted indicating that waters have exceeded public health standards.

Data and information on the number of beach posting were summarized by the County of San Diego in their annual San Diego County Beach Closure and Advisory Reports. The reporting period was from January 2001 to December 2007. Data used was the number of days the beach was posted with an Advisory when the ocean or bay failed to meet the bacteriological standards.
Data Reference: County of Orange. March 2007. Annual Ocean and Bay Water Quality Report, 2006.
  Department of Environmental Health, Land and Water Quality Division. San Diego County Beach Closure and Advisory Report.
 
Water Quality Objective/Criterion: California Code of Regulations. Title 17, Section 7960.

(a) When a public beach or public water-contact sports area fails to meet any of the standards as set forth in Section 7957 or 7958 above, the local health officer or the Department, after taking into consideration the causes therefor, may at his or its discretion close, post with warning signs, or otherwise restrict use of said public beach or public water-contact sports area, until such time as corrective action has been taken and the standards as set forth in 7957 and 7958 above are met.
Objective/Criterion Reference: California Code of Regulations, Title 17, Section 7960.
 
Evaluation Guideline:
Guideline Reference: Water Quality Control Plan Ocean Waters of California. California Ocean Plan 2005. Sacramento, CA: State Water Resources Control Board, California Environmental Protection Agency
 
Spatial Representation: Bacteriological monitoring samples were collected at Bahia Point in Mission Bay.
Temporal Representation: The beach posting covers the time frame of January 2001 -December 2007.
Environmental Conditions:
QAPP Information: Quality control for the bacteria analysis portion was conducted in accordance with the County of San Diego, Department Public Health Laboratory Quality Assurance Manual.
QAPP Information Reference(s): County of San Diego, 2006. Department Public Health Laboratory, Quality Assurance Manual, December 2006.
 
LOE ID: 28668
 
Pollutant: Enterococcus
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 399
Number of Exceedances: 64
 
Data and Information Type: PWS pathogen monitoring (ambient water)
Data Used to Assess Water Quality: Beach monitoring data was collected by the County of San Diego from January 1999 through October 2007. A total of 399 single samples were collected with 64 samples exceeding the single sample water quality objective.
Data Reference: Department of Environmental Health, Ocean & Bay Recreational Water Quality Program, 2007. AB 411 monitoring data 1999 to 2007.
 
Water Quality Objective/Criterion: Geomean: Enterococcus density shall not exceed 35 per 100 ml.

Single Sample Maximum: Enterococcus density shall not exceed 104 per 100 ml (SWRCB, 2005).
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 from Bahia Point, San Diego, California. Station identification number is MB-160.
Temporal Representation: Samples were collected from January 1999 through October 2007.
Environmental Conditions:
QAPP Information: Quality control for the bacteria analysis portion was conducted in accordance with the County of San Diego, Department Public Health Laboratory Quality Assurance Manual.
QAPP Information Reference(s): County of San Diego, 2006. Department Public Health Laboratory, Quality Assurance Manual, December 2006.
 
LOE ID: 28669
 
Pollutant: Enterococcus
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 79
Number of Exceedances: 16
 
Data and Information Type: PWS pathogen monitoring (ambient water)
Data Used to Assess Water Quality: Beach monitoring data was collected by the County of San Diego from January 1999 through October 2007. A total of 399 single samples were collected with 79 monthly geomeans calculated. Sixteen of the 79 geomeans exceeded the geomean water quality objective.
Data Reference: Department of Environmental Health, Ocean & Bay Recreational Water Quality Program, 2007. AB 411 monitoring data 1999 to 2007.
 
Water Quality Objective/Criterion: Geomean: Enterococcus density shall not exceed 35 per 100 ml.

Single Sample Maximum: Enterococcus density shall not exceed 104 per 100 ml (SWRCB, 2005).
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 from Bahia Point, San Diego, California. Station identification number is MB-160.
Temporal Representation: Samples were collected from January 1999 through October 2007.
Environmental Conditions:
QAPP Information: Quality control for the bacteria analysis portion was conducted in accordance with the County of San Diego, Department Public Health Laboratory Quality Assurance Manual.
QAPP Information Reference(s): County of San Diego, 2006. Department Public Health Laboratory, Quality Assurance Manual, December 2006.
 
DECISION ID
16636
 
Pollutant: Total Coliform
Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Source Unknown
Expected TMDL Completion Date: 2019
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: In 2006, 'Mission Bay Shoreline' was listed for Indicator Bacteria. For 2008, the 2006 Mission Bay Shoreline segment has been split into smaller segments and each represents an area near the sampling location of the data being assessed. 'Mission Bay Shoreline, at Bahia Point' is one of the sampling locations for Mission Bay Shoreline, and is considered to be part of the original listing.

For this 2008 assessment, the Regional Board has chosen to replace the 'indicator bacteria' listing with separate assessments of the specific indicator bacteria, such as total coliform, fecal coliform, and enterococcus, for removal or non-removal from the 303(d) list.

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.

Six lines of evidence are available in the administrative record to assess this pollutant. Seventy-five of 397 of the samples exceed the Basin Plan water quality objective for Shellfish Harvesting.

In LOEs 28646 and 28740, the Regional Board calculated exceedances for samples taken only during storm events. This information was not used in determining listing decisions, but is of interest to the Regional Board and has been included as additional anecdotal information.

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 from the 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. Seventy-five of 397 samples exceeded the Shellfish Harvesting water quality objective and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy.
4. 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 16636
 
LOE ID: 30107
 
Pollutant: Indicator Bacteria
LOE Subgroup: Health Advisories
Matrix: -N/A
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 2555
Number of Exceedances: 128
 
Data and Information Type: PWS pathogen monitoring (ambient water)
Data Used to Assess Water Quality: For the period from January 2001 to December 2007, there were 128 beach advisory days for this location. When a bacteriological sample exceeds water quality standards, signs are posted indicating that waters have exceeded public health standards.

Data and information on the number of beach posting were summarized by the County of San Diego in their annual San Diego County Beach Closure and Advisory Reports. The reporting period was from January 2001 to December 2007. Data used was the number of days the beach was posted with an Advisory when the ocean or bay failed to meet the bacteriological standards.
Data Reference: County of Orange. March 2007. Annual Ocean and Bay Water Quality Report, 2006.
  Department of Environmental Health, Land and Water Quality Division. San Diego County Beach Closure and Advisory Report.
 
Water Quality Objective/Criterion: California Code of Regulations. Title 17, Section 7960.

(a) When a public beach or public water-contact sports area fails to meet any of the standards as set forth in Section 7957 or 7958 above, the local health officer or the Department, after taking into consideration the causes therefor, may at his or its discretion close, post with warning signs, or otherwise restrict use of said public beach or public water-contact sports area, until such time as corrective action has been taken and the standards as set forth in 7957 and 7958 above are met.
Objective/Criterion Reference: California Code of Regulations, Title 17, Section 7960.
 
Evaluation Guideline:
Guideline Reference: Water Quality Control Plan Ocean Waters of California. California Ocean Plan 2005. Sacramento, CA: State Water Resources Control Board, California Environmental Protection Agency
 
Spatial Representation: Bacteriological monitoring samples were collected at Bahia Point in Mission Bay.
Temporal Representation: The beach posting covers the time frame of January 2001 -December 2007.
Environmental Conditions:
QAPP Information: Quality control for the bacteria analysis portion was conducted in accordance with the County of San Diego, Department Public Health Laboratory Quality Assurance Manual.
QAPP Information Reference(s): County of San Diego, 2006. Department Public Health Laboratory, Quality Assurance Manual, December 2006.
 
LOE ID: 28644
 
Pollutant: Total Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 397
Number of Exceedances: 75
 
Data and Information Type: PWS pathogen monitoring (ambient water)
Data Used to Assess Water Quality: Beach monitoring data was collected by the County of San Diego from January 1999 through October 2007. A total of 397 single samples were collected with 75 samples exceeded the single sample water quality objective.
Data Reference: Department of Environmental Health, Ocean & Bay Recreational Water Quality Program, 2007. AB 411 monitoring data 1999 to 2007.
 
Water Quality Objective/Criterion: From the Ocean Plan the median coliform density shall not exceed 70 per 100ml, and not more than 10 percent of the samples shall exceed 230 per 100ml (SWRCB, 2005).
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 Bahia Point, San Diego, California. Station identification number is MB-160.
Temporal Representation: Samples were collected from January 1999 through October 2007.
Environmental Conditions:
QAPP Information: Quality control for the bacteria analysis portion was conducted in accordance with the County of San Diego, Department Public Health Laboratory Quality Assurance Manual.
QAPP Information Reference(s): County of San Diego, 2006. Department Public Health Laboratory, Quality Assurance Manual, December 2006.
 
LOE ID: 28734
 
Pollutant: Total Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 79
Number of Exceedances: 1
 
Data and Information Type: PWS pathogen monitoring (ambient water)
Data Used to Assess Water Quality: Beach monitoring data was collected from January 1999 through October 2007. A total of 397 single samples were collected with 79 monthly geomeans calculated. One of the 79 geomeans exceeded the geomean water quality objective.
Data Reference: Department of Environmental Health, Ocean & Bay Recreational Water Quality Program, 2007. AB 411 monitoring data 1999 to 2007.
 
Water Quality Objective/Criterion: Geomean: Total coliform density shall not exceed 1,000 per 100ml;

Single Sample Maximum: Total coliform density shall not exceed 10,000 per 100ml (SWRCB, 2005).
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 from Bahia Point, San Diego, California. Station identification number is MB-160.
Temporal Representation: Samples were collected from January 1999 through October 2007.
Environmental Conditions:
QAPP Information: Quality control for the bacteria analysis portion was conducted in accordance with the County of San Diego, Department Public Health Laboratory Quality Assurance Manual.
QAPP Information Reference(s): County of San Diego, 2006. Department Public Health Laboratory, Quality Assurance Manual, December 2006.
 
LOE ID: 28740
 
Pollutant: Total Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 15
Number of Exceedances: 3
 
Data and Information Type: PWS pathogen monitoring (ambient water)
Data Used to Assess Water Quality: Beach monitoring data was collected by the County of San Diego from January 1999 through October 2007. A total of 397 single samples were collected with 15 samples correlated with a storm event. Three of the 15 samples exceeded the single sample water quality objective. This information will not be used in determining a listing decision, but is of interest to the Regional Board and has been included here as additional anecdotal information.
Data Reference: National Weather Service Forecast Office, San Diego, California, Chronological Regional Temperature and Precipitation Listings by Station
  Department of Environmental Health, Ocean & Bay Recreational Water Quality Program, 2007. AB 411 monitoring data 1999 to 2007.
 
Water Quality Objective/Criterion: Geomean: Total coliform density shall not exceed 1,000 per 100ml;

Single Sample Maximum: Total coliform density shall not exceed 10,000 per 100ml (SWRCB, 2005).
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 from Bahia Point, San Diego, California. Station identification number is MB-160.
Temporal Representation: Samples were collected from January 1999 through October 2007.
Environmental Conditions: Comparisons were made for all data and data associated with storm events. A storm event was defined as 0.2 inches of rainfall within a 72 hour period.

Analyzing only storm water bacteria data is important because the majority of beach monitoring data covers the months of April through October. The data may not capture the full impacts of seasonal storm events and high bacteria levels due to storm water runoff because much of the wet season for Southern California occurs in November through March.
QAPP Information: Quality control for the bacteria analysis portion was conducted in accordance with the County of San Diego, Department Public Health Laboratory Quality Assurance Manual.
QAPP Information Reference(s): County of San Diego, 2006. Department Public Health Laboratory, Quality Assurance Manual, December 2006.
 
LOE ID: 28746
 
Pollutant: Total Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 397
Number of Exceedances: 8
 
Data and Information Type: PWS pathogen monitoring (ambient water)
Data Used to Assess Water Quality: Beach monitoring data was collected by the County of San Diego from January 1999 through October 2007. A total of 397 single samples were collected with eight samples exceeding the single sample water quality objective.
Data Reference: National Weather Service Forecast Office, San Diego, California, Chronological Regional Temperature and Precipitation Listings by Station
  Department of Environmental Health, Ocean & Bay Recreational Water Quality Program, 2007. AB 411 monitoring data 1999 to 2007.
 
Water Quality Objective/Criterion: Single Sample Maximum: Total coliform density shall not exceed 10,000 per 100ml (SWRCB, 2005).
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 from Bahia Point, San Diego, California. Station identification number is MB-160.
Temporal Representation: Samples were collected from January 1999 through October 2007.
Environmental Conditions:
QAPP Information: Quality control for the bacteria analysis portion was conducted in accordance with the County of San Diego, Department Public Health Laboratory Quality Assurance Manual.
QAPP Information Reference(s): County of San Diego, 2006. Department Public Health Laboratory, Quality Assurance Manual, December 2006.
 
LOE ID: 30338
 
Pollutant: Indicator Bacteria
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 2933
Number of Exceedances: 959
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Below is a copy of the 2006 LOE for the data supporting the listing of Mission Bay Shoreline:

Available data indicate sufficient exceedances of bacterial indicator objectives. There were 576 out of 3662 samples exceeding the single sample maximum for enterococci, 959 out of 2933 exceedances of the geomean enterococci, and 333 out samples exceeding the single sample maximum for fecal coliform (USEPA, 2007).
Data Reference: Placeholder reference 2006 303(d)
 
Water Quality Objective/Criterion: Title 17 C.C.R. Section 7958 states: 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.

Based on the mean of the logarithms of the results of at least five weekly samples during any 30-day sampling period, the density of bacteria in water from any sampling station at a public beach or public water contact sports area, shall not exceed:
(A) 1,000 total coliform bacteria per 100 milliliters; or
(B) 200 fecal coliform bacteria per 100 milliliters; or
(C) 35 enterococcus bacteria per 100 milliliters (DHS, 1999).
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: In 2006, data from sampling sites along the Mission Bay shoreline were aggregated for the assessment. For 2008, the 2006 Mission Bay Shoreline segment has been split into smaller segments and each represents an area near the sampling location of the data being assessed. 'Mission Bay Shoreline, at Bahia Point ' is one of the sampling locations for Mission Bay Shoreline and is considered to be part of the original listing
Temporal Representation: From 03/21/2000-10/30/2005.
Environmental Conditions:
QAPP Information: Data record: 2000-2005, San Diego County Health Dept.
QAPP Information Reference(s):
 
LOE ID: 28646
 
Pollutant: Total Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 15
Number of Exceedances: 9
 
Data and Information Type: PWS pathogen monitoring (ambient water)
Data Used to Assess Water Quality: Beach monitoring data was collected by the County of San Diego from January 1999 through October 2007. A total of 397 single samples were collected with 15 samples correlated with a storm event. Nine of the 15 samples exceeded the single sample water quality objective. This information will not be used in determining a listing decision, but is of interest to the Regional Board and has been included here as additional anecdotal information.
Data Reference: National Weather Service Forecast Office, San Diego, California, Chronological Regional Temperature and Precipitation Listings by Station
  Department of Environmental Health, Ocean & Bay Recreational Water Quality Program, 2007. AB 411 monitoring data 1999 to 2007.
 
Water Quality Objective/Criterion: From the Ocean Plan the median coliform density shall not exceed 70 per 100ml, and not more than 10 percent of the samples shall exceed 230 per 100ml (SWRCB, 2005).
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 from Bahia Point, San Diego, California. Station identification number is MB-160.
Temporal Representation: Samples were collected from January 1999 through December 2007.
Environmental Conditions: Comparisons were made for all data and data associated with storm events. A storm event was defined as 0.2 inches of rainfall within a 72 hour period.

Analyzing only storm water bacteria data is important because the majority of beach monitoring data covers the months of April through October. The data may not capture the full impacts of seasonal storm events and high bacteria levels due to storm water runoff because much of the wet season for Southern California occurs in November through March.
QAPP Information: Quality control for the bacteria analysis portion was conducted in accordance with the County of San Diego, Department Public Health Laboratory Quality Assurance Manual.
QAPP Information Reference(s): County of San Diego, 2006. Department Public Health Laboratory, Quality Assurance Manual, December 2006.