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

Supporting Information

Regional Board 3 - Central Coast Region

Water Body Name: Pacific Ocean at Natural Bridges Beach
Water Body ID: CAC3041103120100418161504
Water Body Type: Coastal & Bay Shoreline
 
DECISION ID
129424
Region 3     
Pacific Ocean at Natural Bridges Beach
 
Pollutant: Total Coliform
Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2018)
Revision Status Revised
Sources: No Source Analysis Available
Expected TMDL Completion Date: 2035
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for removal from the CWA 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.

Three lines of evidence are available in the administrative record to assess this pollutant. Seven of the 59 median samples exceeded the SHELL total coliform water quality objective and 11 of the 59 10% threshold exceedance samples exceeded the SHELL total coliform water quality objective.

Based on the readily available data and information, the weight of evidence indicates that there is not sufficient justification for removing this water segment-pollutant combination from 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. Eleven of the 59 10% threshold exceedance samples exceeded the SHELL total coliform water quality objective and this does 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.

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.
 
Regional Board Decision 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.
 
State Board Review of Regional Board Conclusion and Recommendation: 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.
 
State Board Decision Recommendation: After review of the available data and information, SWRCB 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.
 
 
Line of Evidence (LOE) for Decision ID 129424, Total Coliform
Region 3     
Pacific Ocean at Natural Bridges Beach
 
LOE ID: 218057
 
Pollutant: Total Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 59
Number of Exceedances: 7
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Pacific Ocean at Natural Bridges Beach to determine beneficial use support and the results are as follows: 7 of the 59 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: Data file of Region 3 Beachwatch Data. Includes data from all coastal counties in Region 3 including: , Santa Barbara, Santa Cruz, San Luis Obispo, Monterey, Ventura, and San Mateo 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): O530
Temporal Representation: The samples were collected between the days of 2010-09-09 and 2019-06-10 .
Environmental Conditions:
QAPP Information: QAPP for 2020 Santa Cruz County Beachwatch data.
QAPP Information Reference(s): QAPP for 2020 Santa Cruz County Beachwatch data.
 
Line of Evidence (LOE) for Decision ID 129424, Total Coliform
Region 3     
Pacific Ocean at Natural Bridges Beach
 
LOE ID: 56359
 
Pollutant: Total Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 155
Number of Exceedances: 28
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Beach Watch data for Pacific Ocean at Natural Bridges Beach to determine beneficial use support and results are as follows: 28 of 155 samples exceed the criterion for Coliform, Total.
Data Reference: Data for Region 3 Beach Watch.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California Ocean Plan (2009) states the following: At all areas where shellfish may be harvested for human consumption, the following bacterial objectives shall be maintained throughout the water column: Ten percent of the samples collected during any 30-day period shall not exceed 230 MPN/100mL.
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 at Natural Bridges Beach was collected at 1 monitoring site [ Natural Bridges Beach]
Temporal Representation: Data was collected over the time period 1/3/2007-8/23/2010.
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 129424, Total Coliform
Region 3     
Pacific Ocean at Natural Bridges Beach
 
LOE ID: 218022
 
Pollutant: Total Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Shellfish Harvesting
 
Number of Samples: 59
Number of Exceedances: 11
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Pacific Ocean at Natural Bridges Beach to determine beneficial use support and the results are as follows: 11 of the 59 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: Data file of Region 3 Beachwatch Data. Includes data from all coastal counties in Region 3 including: , Santa Barbara, Santa Cruz, San Luis Obispo, Monterey, Ventura, and San Mateo 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): O530
Temporal Representation: The samples were collected between the days of 2010-09-09 and 2019-06-10 .
Environmental Conditions:
QAPP Information: QAPP for 2020 Santa Cruz County Beachwatch data.
QAPP Information Reference(s): QAPP for 2020 Santa Cruz County Beachwatch data.
 
 
DECISION ID
129422
Region 3     
Pacific Ocean at Natural Bridges Beach
 
Pollutant: Enterococcus
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 3.2 of the Listing Policy. Under section 3.2 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. Forty-five of the 456 GM samples exceed the REC-1 enterococci water quality objective.

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. Forty-five of the 456 GM samples exceed the REC-1 enterococci water quality objective 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 the CWA section 303(d) List under section 3.3 of the Listing Policy, as applicable, using the enterococci objective.

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 the CWA section 303(d) List under section 3.3 of the Listing Policy, as applicable, using the enterococci objective.

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 the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded.
 
 
Line of Evidence (LOE) for Decision ID 129422, Enterococcus
Region 3     
Pacific Ocean at Natural Bridges Beach
 
LOE ID: 56356
 
Pollutant: Enterococcus
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 141
Number of Exceedances: 5
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Five of the 141 geomeans exceeded the entercoccus objective.
Data Reference: Data for Region 3 Beach Watch.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The geometric mean standard for enterococcus 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 from station Natural Bridges Beach.
Temporal Representation: Samples were collected approximately once a week from 2007 to 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 129422, Enterococcus
Region 3     
Pacific Ocean at Natural Bridges Beach
 
LOE ID: 218111
 
Pollutant: Enterococcus
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 106
Number of Exceedances: 20
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Pacific Ocean at Natural Bridges Beach to determine beneficial use support and the results are as follows: 20 of the 106 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: Data file of Region 3 Beachwatch Data. Includes data from all coastal counties in Region 3 including: , Santa Barbara, Santa Cruz, San Luis Obispo, Monterey, Ventura, and San Mateo 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): O530
Temporal Representation: The samples were collected between the days of 2010-09-09 and 2019-06-10 .
Environmental Conditions:
QAPP Information: QAPP for 2020 Santa Cruz County Beachwatch data.
QAPP Information Reference(s): QAPP for 2020 Santa Cruz County Beachwatch data.
 
Line of Evidence (LOE) for Decision ID 129422, Enterococcus
Region 3     
Pacific Ocean at Natural Bridges Beach
 
LOE ID: 218150
 
Pollutant: Enterococcus
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 456
Number of Exceedances: 45
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Pacific Ocean at Natural Bridges Beach to determine beneficial use support and the results are as follows: 45 of the 456 samples exceeded the geomean water quality threshold for Enterococcus. This is a six week rolling geomean that is calculated weekly.
Data Reference: Data file of Region 3 Beachwatch Data. Includes data from all coastal counties in Region 3 including: , Santa Barbara, Santa Cruz, San Luis Obispo, Monterey, Ventura, and San Mateo 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): O530
Temporal Representation: The samples were collected between the days of 2010-09-09 and 2019-06-10 .
Environmental Conditions:
QAPP Information: QAPP for 2020 Santa Cruz County Beachwatch data.
QAPP Information Reference(s): QAPP for 2020 Santa Cruz County Beachwatch data.
 
Line of Evidence (LOE) for Decision ID 129422, Enterococcus
Region 3     
Pacific Ocean at Natural Bridges Beach
 
LOE ID: 56355
 
Pollutant: Enterococcus
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 156
Number of Exceedances: 6
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Beach Watch Program data that is collected by each County's Environmental Health Department for Pacific Ocean at Natural Bridges Beach to determine beneficial use support and results are as follows: 6 of 156 samples exceed the criterion for Enterococci.
Data Reference: Data for Region 3 Beach Watch.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Ocean Plan (SWRCB 2005) single sample maximum for enterococcus density shall not exceed 104 per 100 mL.
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: Data for this line of evidence for Pacific Ocean at Natural Bridges Beach was collected at 1 monitoring site [ Natural Bridges Beach]
Temporal Representation: Data was collected over the time period 1/3/2007-8/23/2010.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Water Board staff assessed Beach Watch Program data that is collected by each County's Environmental Health Department. There is no QA Project Plan but instead each County follows their own Quality Assurance Procedures
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 129422, Enterococcus
Region 3     
Pacific Ocean at Natural Bridges Beach
 
LOE ID: 20143
 
Pollutant: Enterococcus
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 108
Number of Exceedances: 1
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed data for Pacific Ocean at Natural Bridges Beach to determine beneficial use support and results are as follows: 1 of 108 samples exceed the criterion for Enterococci.
Data Reference: AB 411 Data for 2004
  AB 411 Data for 2005
  AB 411 Data for 2006
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Ocean Plan (SWRCB 2005) states that the single sample maximum for Enterococcus shall not exceed 104 MPN/100 mL.
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: Data for this line of evidence for Pacific Ocean at Natural Bridges Beach was collected at one AB411 monitoring site (Natural Bridges Beach)
Temporal Representation: Data was collected over the time period 3/8/2004 - 12/26/2006. This includes weekly AB411 monitoring between April 1 and October 31 of each year.
Environmental Conditions:
QAPP Information: QA information not available
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 129422, Enterococcus
Region 3     
Pacific Ocean at Natural Bridges Beach
 
LOE ID: 20142
 
Pollutant: Enterococcus
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 26
Number of Exceedances: 1
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed data for Pacific Ocean at Natural Bridges Beach to determine beneficial use support and results are as follows: 1 of 26 samples exceed the criterion for Enterococci.
Data Reference: AB 411 Data for 2004
  AB 411 Data for 2005
  AB 411 Data for 2006
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Ocean Plan (SWRCB 2005) states that the geometric mean for Enterococcus shall not exceed 35 MPN/100 mL.
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: Data for this line of evidence for Pacific Ocean at Natural Bridges Beach was collected at one AB411 monitoring site (Natural Bridges Beach)
Temporal Representation: Data was collected over the time period 3/8/2004 - 12/26/2006. This includes weekly AB411 monitoring between April 1 and October 31 of each year.
Environmental Conditions:
QAPP Information: QA information not available
QAPP Information Reference(s):
 
 
DECISION ID
129423
Region 3     
Pacific Ocean at Natural Bridges Beach
 
Pollutant: Fecal Coliform
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 3.2 of the Listing Policy. Under section 3.2 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. Zero of the 60 SSM samples and 0 of the 15 GM samples exceed the REC-1 fecal coliform water quality objective. As there were an insufficient number of GM samples, the decision will be based on SSM samples.

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 the 60 SSM samples exceed the REC-1 fecal coliform water quality objective 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 the CWA section 303(d) List under section 3.3 of the Listing Policy, as applicable, using the fecal coliform objective.

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 fecal coliform 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 the CWA section 303(d) List under section 3.3 of the Listing Policy, as applicable, using the fecal coliform objective.

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 fecal coliform 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 the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded.
 
 
Line of Evidence (LOE) for Decision ID 129423, Fecal Coliform
Region 3     
Pacific Ocean at Natural Bridges Beach
 
LOE ID: 218109
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 60
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Pacific Ocean at Natural Bridges Beach to determine beneficial use support and the results are as follows: 0 of the 60 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: Data file of Region 3 Beachwatch Data. Includes data from all coastal counties in Region 3 including: , Santa Barbara, Santa Cruz, San Luis Obispo, Monterey, Ventura, and San Mateo 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): O530
Temporal Representation: The samples were collected between the days of 2018-03-05 and 2019-06-10 .
Environmental Conditions:
QAPP Information: QAPP for 2020 Santa Cruz County Beachwatch data.
QAPP Information Reference(s): QAPP for 2020 Santa Cruz County Beachwatch data.
 
Line of Evidence (LOE) for Decision ID 129423, Fecal Coliform
Region 3     
Pacific Ocean at Natural Bridges Beach
 
LOE ID: 20141
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 85
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed data for Pacific Ocean at Natural Bridges Beach to determine beneficial use support and results are as follows: 0 of 85 samples exceed the criterion for Coliform, Fecal.
Data Reference: AB 411 Data for 2004
  AB 411 Data for 2005
  AB 411 Data for 2006
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Ocean Plan (SWRCB 2005) states that the single sample maximum for fecal coliform shall not exceed 400 MPN/100 mL.
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: Data for this line of evidence for Pacific Ocean at Natural Bridges Beach was collected at one AB411 monitoring site (Natural Bridges Beach)
Temporal Representation: Data was collected over the time period 3/8/2004 - 12/26/2006. This includes weekly AB411 monitoring between April 1 and October 31 of each year.
Environmental Conditions:
QAPP Information: QA information not available
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 129423, Fecal Coliform
Region 3     
Pacific Ocean at Natural Bridges Beach
 
LOE ID: 218058
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 15
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data for Pacific Ocean at Natural Bridges Beach to determine beneficial use support and the results are as follows: 0 of the 15 samples exceeded the water quality threshold for Coliform, Fecal. The water quality threshold is based on a 30-Day rolling geomean.
Data Reference: Data file of Region 3 Beachwatch Data. Includes data from all coastal counties in Region 3 including: , Santa Barbara, Santa Cruz, San Luis Obispo, Monterey, Ventura, and San Mateo 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): O530
Temporal Representation: The samples were collected between the days of 2018-03-05 and 2019-06-10 .
Environmental Conditions:
QAPP Information: QAPP for 2020 Santa Cruz County Beachwatch data.
QAPP Information Reference(s): QAPP for 2020 Santa Cruz County Beachwatch data.
 
Line of Evidence (LOE) for Decision ID 129423, Fecal Coliform
Region 3     
Pacific Ocean at Natural Bridges Beach
 
LOE ID: 20140
 
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: PATHOGEN MONITORING
Data Used to Assess Water Quality: Central Coast Regional Board Staff assessed data for Pacific Ocean at Natural Bridges Beach to determine beneficial use support and results are as follows: 0 of 22 samples exceed the criterion for Coliform, Fecal.
Data Reference: AB 411 Data for 2004
  AB 411 Data for 2005
  AB 411 Data for 2006
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: California Ocean Plan (SWRCB 2005) states that the 30-day geometric mean for fecal coliform shall not exceed 200 MPN/100 mL.
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: Data for this line of evidence for Pacific Ocean at Natural Bridges Beach was collected at one AB411 monitoring site (Natural Bridges Beach)
Temporal Representation: Data was collected over the time period 3/8/2004 - 12/26/2006. This includes weekly AB411 monitoring between April 1 and October 31 of each year.
Environmental Conditions:
QAPP Information: QA information not available
QAPP Information Reference(s):