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, Batiquitos HSA, at South Carlsbad State Beach (Encina Creek Outlet)
Water Body ID:	CAC9045100020111101100825
Water Body Type:	Coastal & Bay Shoreline


DECISION ID	127916	Region 9
Pacific Ocean Shoreline, Batiquitos HSA, at South Carlsbad State Beach (Encina Creek Outlet)

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)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the 392 samples exceed the GM threshold for Enterococci. Zero of 180 samples exceed the GM threshold for Fecal Coliform. 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. Zero of 392 samples exceeded the Enterococci water quality threshold and zero of 180 samples exceeded the Fecal Coliform water quality threshold for the protection of REC-1, and this does not exceed the allowable frequency listed in Table 3.2 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. 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 because applicable water quality standards are not being exceeded.

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:	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 127916, Indicator Bacteria	Region 9
Pacific Ocean Shoreline, Batiquitos HSA, at South Carlsbad State Beach (Encina Creek Outlet)

LOE ID:

220276

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

442

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data for Pacific Ocean Shoreline, Batiquitos HSA, at South Carlsbad State Beach (Encina Creek Outlet) to determine beneficial use support and the results are as follows: 1 of the 442 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): EN-030

Temporal Representation:

The samples were collected between the days of 2010-09-07 and 2019-06-10 .

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 127916, Indicator Bacteria	Region 9
Pacific Ocean Shoreline, Batiquitos HSA, at South Carlsbad State Beach (Encina Creek Outlet)

LOE ID:

220246

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

180

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data for Pacific Ocean Shoreline, Batiquitos HSA, at South Carlsbad State Beach (Encina Creek Outlet) to determine beneficial use support and the results are as follows: 0 of the 180 samples exceeded the water quality threshold for Coliform, Fecal. The water quality threshold is based on a 30-Day rolling geomean.

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 30 day geometric mean of fecal coliform density not exceed 200 per 100 mL, calculated based on the five most recent samples from each site.

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): EN-030

Temporal Representation:

The samples were collected between the days of 2010-09-07 and 2019-06-10 .

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 127916, Indicator Bacteria	Region 9
Pacific Ocean Shoreline, Batiquitos HSA, at South Carlsbad State Beach (Encina Creek Outlet)

LOE ID:

220245

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

392

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data for Pacific Ocean Shoreline, Batiquitos HSA, at South Carlsbad State Beach (Encina Creek Outlet) to determine beneficial use support and the results are as follows: 0 of the 392 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): EN-030

Temporal Representation:

The samples were collected between the days of 2010-09-07 and 2019-06-10 .

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 127916, Indicator Bacteria	Region 9
Pacific Ocean Shoreline, Batiquitos HSA, at South Carlsbad State Beach (Encina Creek Outlet)

LOE ID:

220332

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

103

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data for Pacific Ocean Shoreline, Batiquitos HSA, at South Carlsbad State Beach (Encina Creek Outlet) to determine beneficial use support and the results are as follows: 3 of the 103 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): EN-030

Temporal Representation:

The samples were collected between the days of 2010-09-07 and 2019-06-10 .

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 127916, Indicator Bacteria	Region 9
Pacific Ocean Shoreline, Batiquitos HSA, at South Carlsbad State Beach (Encina Creek Outlet)

LOE ID:

74565

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

128

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Zero of the 128 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 Encina Creek outlet site.

Temporal Representation:

Samples were collected from January 2008 to August 2010.

Environmental Conditions:

QAPP Information:

The samples were collected for the Beach Watch program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 127916, Indicator Bacteria	Region 9
Pacific Ocean Shoreline, Batiquitos HSA, at South Carlsbad State Beach (Encina Creek Outlet)

LOE ID:

77588

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Shellfish Harvesting

Number of Samples:

128

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

None of the 128 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 California Ocean Plan states that at all areas where shellfish may be harvested for human consumption, the median total coliform density 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:

California Ocean Plan Water Quality Control Plan Ocean Waters of California 2009

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at Pacific Ocean Shoreline, Batiquitos HSA, at South Carlsbad State Beach (Encina Creek Outlet).

Temporal Representation:

The samples were collected from January 2008 through August 2010.

Environmental Conditions:

QAPP Information:

The samples were collected for the beach watch program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 127916, Indicator Bacteria	Region 9
Pacific Ocean Shoreline, Batiquitos HSA, at South Carlsbad State Beach (Encina Creek Outlet)

LOE ID:

74567

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Shellfish Harvesting

Number of Samples:

134

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed BW data for Pacific Ocean Shoreline, Batiquitos HSA, at South Carlsbad State Beach (Encina Creek Outlet) to determine beneficial use support and results are as follows: 0 of 134 samples exceed the criterion for Coliform, Total.

Data Reference:

Data for Region 9 Beach Watch.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Ocean Plan states that at all areas where shellfish may be harvested for human consumption, not more than 10 percent of the samples shall exceed 230 per 100 mL.

Objective/Criterion Reference:

California Ocean Plan Water Quality Control Plan Ocean Waters of California 2009

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Pacific Ocean Shoreline, Batiquitos HSA, at South Carlsbad State Beach (Encina Creek Outlet) was collected at 1 monitoring site [ Encina Creek outlet]

Temporal Representation:

Data was collected over the time period 1/7/2008-8/23/2010.

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 127916, Indicator Bacteria	Region 9
Pacific Ocean Shoreline, Batiquitos HSA, at South Carlsbad State Beach (Encina Creek Outlet)

LOE ID:

74566

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

128

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Zero of the 128 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 Encina Creek outlet site.

Temporal Representation:

Samples were collected approximately once a week from January 2008 to August 2010.

Environmental Conditions:

QAPP Information:

The samples were collected for the beach watch program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 127916, Indicator Bacteria	Region 9
Pacific Ocean Shoreline, Batiquitos HSA, at South Carlsbad State Beach (Encina Creek Outlet)

LOE ID:

74572

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

128

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Zero of the 128 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 Encina Creek outlet site.

Temporal Representation:

Samples were collected from January 2008 to August 2010.

Environmental Conditions:

QAPP Information:

The samples were collected for the Beach Watch program.

QAPP Information Reference(s):