Final California 2020 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 9 - San Diego Region

Water Body Name: Mission Bay Shoreline, at Santa Clara Point
Water Body ID: CAC9075100020111027111540
Water Body Type: Coastal & Bay Shoreline
 
DECISION ID
97660
Region 9     
Mission Bay Shoreline, at Santa Clara Point
 
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: Pollution
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 one line(s) of evidence are necessary to assess listing status.

Five lines of evidence are available in the administrative record to assess this pollutant. With the latest data, zero of 22 geomean samples exceed the water quality objective for enterococcus for the protection of REC-1 beneficial use.

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 CWA 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. With the latest data, zero of 22 geomean samples exceed the water quality objective for enterococcus for the protection of REC-1 beneficial use and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 26 samples is needed to determine if a beneficial use is fully supported using table 3.2.
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, 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 97660, Indicator Bacteria
Region 9     
Mission Bay Shoreline, at Santa Clara Point
 
LOE ID: 74365
 
Pollutant: Total Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 24
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BW data for Mission Bay Shoreline, at Santa Clara Point to determine beneficial use support and results are as follows: 0 of 27 samples exceed the criterion for Coliform, Total.
Data Reference: Data for Region 9 Beach Watch.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan (Basin Plan 2011)states the following: At all areas where shellfish may be harvested for human consumption, ten percent of the samples collected during any 30-day period shall not exceed 230 MPN/100mL.
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Mission Bay Shoreline, at Santa Clara Point was collected at 1 monitoring site [ Santa Clara Pt. East]
Temporal Representation: Data was collected over the time period 04/02/2008-9/23/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The samples were collected for the Beach Watch program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 97660, Indicator Bacteria
Region 9     
Mission Bay Shoreline, at Santa Clara Point
 
LOE ID: 74364
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 22
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Zero of the 22 geomeans exceeded the objective.
Data Reference: Data for Region 9 Beach Watch.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The standard for fecal coliform states that the coliform density shall not exceed 200 per 100 mL. Water Quality Control Plan for Ocean Waters 2009.
Objective/Criterion Reference: California Ocean Plan Water Quality Control Plan Ocean Waters of California 2009
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected at the Mission Bay, Sail Bay site.
Temporal Representation: Samples were collected approximately once a week from January 2008 to September 2008.
Environmental Conditions:
QAPP Information: The samples were collected for the beach watch program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 97660, Indicator Bacteria
Region 9     
Mission Bay Shoreline, at Santa Clara Point
 
LOE ID: 74363
 
Pollutant: Enterococcus
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 22
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Zero of the 22 geomeans exceeded the objective.
Data Reference: Data for Region 9 Beach Watch.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The geometric mean standard for entercoccus states that the entercoccus density shall not exceed 35 per 100 mL. Water Quality Control Plan for Ocean Waters 2009.
Objective/Criterion Reference: California Ocean Plan Water Quality Control Plan Ocean Waters of California 2009
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected at the Mission Bay, Sail Bay site.
Temporal Representation: Samples were collected approximately once a week from January 2008 to September 2008.
Environmental Conditions:
QAPP Information: The samples were collected for the Beach Watch program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 97660, Indicator Bacteria
Region 9     
Mission Bay Shoreline, at Santa Clara Point
 
LOE ID: 74366
 
Pollutant: Total Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 22
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Zero of the 20 geomeans exceeded the objective.
Data Reference: Data for Region 9 Beach Watch.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The geometric mean standard for total coliform states that the coliform density shall not exceed 1000 per 100 mL. Water Quality Control Plan for Ocean Waters 2009.
Objective/Criterion Reference: California Ocean Plan Water Quality Control Plan Ocean Waters of California 2009
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected at the Mission Bay, Sail Bay site.
Temporal Representation: Samples were collected approximately once a week from January 2008 to September 2008.
Environmental Conditions:
QAPP Information: The samples were collected for the Beach Watch program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 97660, Indicator Bacteria
Region 9     
Mission Bay Shoreline, at Santa Clara Point
 
LOE ID: 77612
 
Pollutant: Total Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 21
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: None of the twenty-one samples exceeded the objective of 70 mpn/100ml applied as a rolling 30 day geomean.
Data Reference: Data for Region 9 Beach Watch.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan for the San Diego Basin states that at all areas where shellfish may be harvested for human consumption, the median total coliform concentration throughout the water column for any 30-day period shall not exceed 70 per 100 mL. Staff applied the objective as a rolling 30 day geometric mean consistent with other state bacteria objectives and with guidance from the National Shellfish Sanitation Program from which the objectives were taken.
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at Mission Bay Shoreline, at Santa Clara Point at station Mission Bay, Sail Bay (MB-135).
Temporal Representation: The samples were collected from April 2008 to September 2008.
Environmental Conditions:
QAPP Information: The samples were collected for the beach watch program.
QAPP Information Reference(s):