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

Supporting Information

Regional Board 9 - San Diego Region

Water Body Name: Pacific Ocean Shoreline, San Luis Rey HU, at Harbor Beach
Water Body ID: CAC9041000020201005056431
Water Body Type: Coastal & Bay Shoreline
 
DECISION ID
127997
Region 9     
Pacific Ocean Shoreline, San Luis Rey HU, at Harbor Beach
 
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: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

The Water Quality Control Plan for Ocean Waters (“Ocean Plan”) contains two bacteria water quality objectives applicable to the REC-1 beneficial use: a fecal coliform water quality objective and an enterococci water quality objective. This waterbody is being considered for placement on or removal from the CWA section 303(d) List under section 3.3 or 4.3 of the Listing Policy, as applicable, using the fecal coliform and enterococci objectives.

In accordance with section 6.1.5.3 of the Listing Policy, data should be representative of the critical timing that the pollutant is expected to impact the waterbody. Indicator bacteria (total coliform, fecal coliform, E. coli, enterococci) populations may fluctuate substantially on a daily, seasonal, or yearly basis. Lacking constant inputs, they do not persist in the environment for a long period and effects are of relatively short duration. As a result, the historic levels of indicator bacteria in the waterbody may be a poor indicator of current risks to human health, particularly when more recent data are available to sufficiently assess the water quality standard. Additionally, water quality conditions in waterbodies may change as a result of management actions that have been implemented to address bacteria. Unrepresentative data may result in incorrectly placing or not placing a water body segment on the list, which could result in the unnecessary expenditure of public resources or missing a human health problem. Historic lines of evidence for data collected prior to 2010 were evaluated pursuant to these considerations and were not used to assess water quality standards attainment because they do not meet the temporal representation requirements of section 6.1.5.3 of the Listing Policy.

For enterococci data, Listing Policy sections 3.3 and 4.3 instructs to use the binomial distribution table in sections 3.2 and 4.2, as applicable. To use the binomial table that uses a four percent exceedance frequency, the data must be collected from coastal beaches from April 1 through October 31 only.
 
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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation: The Water Quality Control Plan for Ocean Waters (“Ocean Plan”) contains two bacteria water quality objectives applicable to the REC-1 beneficial use: a fecal coliform water quality objective and an enterococci water quality objective. This waterbody is being considered for placement on or removal from the CWA section 303(d) List under section 3.3 or 4.3 of the Listing Policy, as applicable, using the fecal coliform and enterococci objectives.

In accordance with section 6.1.5.3 of the Listing Policy, data should be representative of the critical timing that the pollutant is expected to impact the waterbody. Indicator bacteria (total coliform, fecal coliform, E. coli, enterococci) populations may fluctuate substantially on a daily, seasonal, or yearly basis. Lacking constant inputs, they do not persist in the environment for a long period and effects are of relatively short duration. As a result, the historic levels of indicator bacteria in the waterbody may be a poor indicator of current risks to human health, particularly when more recent data are available to sufficiently assess the water quality standard. Additionally, water quality conditions in waterbodies may change as a result of management actions that have been implemented to address bacteria. Unrepresentative data may result in incorrectly placing or not placing a water body segment on the list, which could result in the unnecessary expenditure of public resources or missing a human health problem. Historic lines of evidence for data collected prior to 2010 were evaluated pursuant to these considerations and were not used to assess water quality standards attainment because they do not meet the temporal representation requirements of section 6.1.5.3 of the Listing Policy.

For enterococci data, Listing Policy sections 3.3 and 4.3 instructs to use the binomial distribution table in sections 3.2 and 4.2, as applicable. To use the binomial table that uses a four percent exceedance frequency, the data must be collected from coastal beaches from April 1 through October 31 only.
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 127997, Indicator Bacteria
Region 9     
Pacific Ocean Shoreline, San Luis Rey HU, at Harbor Beach
 
LOE ID: 220330
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Pacific Ocean Shoreline, San Luis Rey HU, at Harbor Beach to determine beneficial use support and the results are as follows: 0 of the 4 samples exceeded the water quality threshold for Coliform, Fecal. The water quality threshold is based on a Single Sample Maximum (SSM) value that is calculated daily.
Data Reference: Coastal Counties in Region 9 including: Orange, San Diego, and Los Angeles counties.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Ocean Plan (SWRCB 2019) states that the Single Sample Maximum fecal coliform density not exceed 400 per 100 mL.
Objective/Criterion Reference: SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): OC-110
Temporal Representation: The samples were collected between the days of 2018-11-13 and 2019-02-12 .
Environmental Conditions:
QAPP Information: QAPP for San Diego County Beachwatch data
QAPP Information Reference(s): QAPP for San Diego County Beachwatch data for the 2020 Integrated Report.
 
Line of Evidence (LOE) for Decision ID 127997, Indicator Bacteria
Region 9     
Pacific Ocean Shoreline, San Luis Rey HU, at Harbor Beach
 
LOE ID: 220529
 
Pollutant: Total Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Pacific Ocean Shoreline, San Luis Rey HU, at Harbor Beach to determine beneficial use support and the results are as follows: 0 of the 4 samples exceeded the water quality threshold for Coliform, Total. The water quality threshold for shellfish is based on the median concentration of Total Coliform at each station, and is calculated as a 30-day rolling median.
Data Reference: Coastal Counties in Region 9 including: Orange, San Diego, and Los Angeles counties.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Ocean Plan (SWRCB 2019) states that the median total coliform density shall not exceed 70 per 100 mL.
Objective/Criterion Reference: SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): OC-110
Temporal Representation: The samples were collected between the days of 2018-11-13 and 2019-06-12 .
Environmental Conditions:
QAPP Information: QAPP for San Diego County Beachwatch data
QAPP Information Reference(s): QAPP for San Diego County Beachwatch data for the 2020 Integrated Report.
 
Line of Evidence (LOE) for Decision ID 127997, Indicator Bacteria
Region 9     
Pacific Ocean Shoreline, San Luis Rey HU, at Harbor Beach
 
LOE ID: 220460
 
Pollutant: Enterococcus
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Pacific Ocean Shoreline, San Luis Rey HU, at Harbor Beach to determine beneficial use support and the results are as follows: 0 of the 8 samples exceeded the Statistical Threshold Value (STV) water quality threshold for Enterococcus. The STV is based on a 10% exceedance rate that is calculated monthly.
Data Reference: Coastal Counties in Region 9 including: Orange, San Diego, and Los Angeles counties.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Ocean Plan (SWRCB 2019) states that the bacteria water quality objective to protect the REC-1 beneficial for all ocean waters for Enterococci is a statistical value threshold (STV) of 110 cfu/100 mL. The STV shall not be exceeded by more than 10 percent of the samples collected in a calendar month, calculated in a static manner.
Objective/Criterion Reference: SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): OC-110
Temporal Representation: The samples were collected between the days of 2018-11-13 and 2019-06-12 .
Environmental Conditions:
QAPP Information: QAPP for San Diego County Beachwatch data
QAPP Information Reference(s): QAPP for San Diego County Beachwatch data for the 2020 Integrated Report.
 
Line of Evidence (LOE) for Decision ID 127997, Indicator Bacteria
Region 9     
Pacific Ocean Shoreline, San Luis Rey HU, at Harbor Beach
 
LOE ID: 220390
 
Pollutant: Total Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Pacific Ocean Shoreline, San Luis Rey HU, at Harbor Beach to determine beneficial use support and the results are as follows: 0 of the 4 samples exceeded the water quality threshold for Coliform, Total. The water quality threshold is based on a 10% exceedance rate that is calculated for a 30-Day peroid.
Data Reference: Coastal Counties in Region 9 including: Orange, San Diego, and Los Angeles counties.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Ocean Plan (SWRCB 2019) states that not more than 10 percent of the total coliform samples shall exceed 230 per 100 mL.
Objective/Criterion Reference: SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): OC-110
Temporal Representation: The samples were collected between the days of 2018-11-13 and 2019-06-12 .
Environmental Conditions:
QAPP Information: QAPP for San Diego County Beachwatch data
QAPP Information Reference(s): QAPP for San Diego County Beachwatch data for the 2020 Integrated Report.
 
Line of Evidence (LOE) for Decision ID 127997, Indicator Bacteria
Region 9     
Pacific Ocean Shoreline, San Luis Rey HU, at Harbor Beach
 
LOE ID: 220241
 
Pollutant: Enterococcus
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Pacific Ocean Shoreline, San Luis Rey HU, at Harbor Beach to determine beneficial use support and the results are as follows: 0 of the 7 samples exceeded the geomean water quality threshold for Enterococcus. This is a six week rolling geomean that is calculated weekly.
Data Reference: Coastal Counties in Region 9 including: Orange, San Diego, and Los Angeles counties.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Ocean Plan (SWRCB 2019) states that the bacteria water quality objective to protect the REC-1 beneficial for all ocean waters for Enterococci is a geometric mean (GM) of 30 cfu/100 mL. The waterbody GM shall not be greater that the GM magnitude in any six-week interval, calculated weekly.
Objective/Criterion Reference: SWRCB. 2005. Water Quality Control Plan, Ocean Waters of California (Ocean Plan). California Environmental Protection Agency, State Water Resources Control Board. February 2, 2019
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): OC-110
Temporal Representation: The samples were collected between the days of 2018-11-13 and 2019-06-12 .
Environmental Conditions:
QAPP Information: QAPP for San Diego County Beachwatch data
QAPP Information Reference(s): QAPP for San Diego County Beachwatch data for the 2020 Integrated Report.