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

# Supporting Information

## Regional Board 3 - Central Coast Region

Water Body Name: | Pacific Ocean at Cowell Beach (Santa Cruz County)
Water Body ID: | CAX3041205320021001213048
Water Body Type: | Coastal & Bay Shoreline

DECISION ID | 10718
Pollutant: | Enterococcus
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
Weight of Evidence: | This water segment-pollutant combination is being considered for placement on the 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. Four lines of evidence are available in the administrative record to assess this water segment-pollutant combination. Data was collected from two different locations along Cowells beach. Lines of evidence #19501 and #19502 summarize data from west of the wharf and #19507 and #19527 summarize data from the bottom of the stairs. Water Board staff assessed the data for each site against two different evaluation criteria (i.e. single sample maximum and geomean). At the site located west of the wharf, 1 of 128 samples exceeded the single sample maximum criterion and 0 of 26 geomean assessments exceeded the geomean criterion. At the monitoring site located at the base of the stairs, 2 of 111 samples exceeded the single sample maximum criterion and 0 of 26 geomean assessments exceeded the geomean criterion. 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 section 303(d) list in the Water Quality Limited Segments category. 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. The exceedance frequency 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.
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 placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10718

LOE ID: | 19502
Pollutant: | Enterococcus
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 128
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 Cowell Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 1 of 128 samples exceed the criterion for Enterococci.
Data Reference: | AB 411 Data for 2004
| AB 411 Data for 2005
| AB 411 Data for 2006
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 Cowell Beach (Santa Cruz County) was collected at one AB411 monitoring site (Cowell Beach West of the Wharf)
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):
LOE ID: | 19527
Pollutant: | Enterococcus
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 111
Number of Exceedances: | 2
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed data for Pacific Ocean at Cowell Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 2 of 111 samples exceed the criterion for Enterococci.
Data Reference: | AB 411 Data for 2004
| AB 411 Data for 2005
| AB 411 Data for 2006
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 Cowell Beach (Santa Cruz County) was collected at one AB411 monitoring site (Cowell's Beach @ the Stairs)
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):
LOE ID: | 19501
Pollutant: | Enterococcus
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 26
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 Cowell Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 0 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
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 Cowell Beach (Santa Cruz County) was collected at one AB411 monitoring site (Cowell Beach West of the Wharf)
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):
LOE ID: | 19507
Pollutant: | Enterococcus
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 26
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 Cowell Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 0 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
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 Cowell Beach (Santa Cruz County) was collected at one AB411 monitoring site (Cowell's Beach @ the Stairs)
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 | 10944
Pollutant: | Escherichia coli (E. Coli)
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
Weight of Evidence: | This water segment-pollutant combination is being considered for placement on the 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. Four lines of evidence are available in the administrative record to assess this water segment-pollutant combination. Data was collected from two different locations on the Cowell beach. Lines of evidence 19503 and 19504 summarize data from west of the wharf and LOEs 19528 and 19529 summarize data from the bottom of the stairs. Water Board staff assessed the data for each site against two different evaluation criteria (i.e. single sample maximum and geomean). At the site located west of the wharf, 0 of 7 samples exceeded the single sample maximum criterion and 1 of 2 geomean assessments exceeded the geomean criterion. At the monitoring site located at the base of the stairs, 0 of 7 samples exceeded the single sample maximum criterion and 0 of 2 geomean assessments exceeded the geomean criterion. 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 section 303(d) list in the Water Quality Limited Segments category. However, there are an insufficient number of samples to make a "use rating" decision. Central Coast Water Board staff require a minimum of 26 samples to make a "use rating" decision of Fully Supporting. 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. None of the sample exceedance rates 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.
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 placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10944

LOE ID: | 19503
Pollutant: | Escherichia coli (E. Coli)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 2
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 Cowell Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 1 of 2 samples exceed the criterion for Escherichia coli.
Data Reference: | AB 411 Data for 2004
| AB 411 Data for 2005
| AB 411 Data for 2006
Water Quality Objective/Criterion: | USEPA Ambient Water Quality Criteria for Bacteria -1986.
Objective/Criterion Reference: | Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
Evaluation Guideline: | Steady State Geometric Mean Indicator Density is 126 MPN/100mL (as stated in Table 4, Page 15).
Guideline Reference: | Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
Spatial Representation: | Data for this line of evidence for Pacific Ocean at Cowell Beach (Santa Cruz County) was collected at one AB411 monitoring site (Cowell Beach West of the Wharf)
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):
LOE ID: | 19504
Pollutant: | Escherichia coli (E. Coli)
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: | Central Coast Regional Board Staff assessed data for Pacific Ocean at Cowell Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Escherichia coli.
Data Reference: | AB 411 Data for 2004
| AB 411 Data for 2005
| AB 411 Data for 2006
Water Quality Objective/Criterion: | USEPA Ambient Water Quality Criteria for Bacteria -1986.
Objective/Criterion Reference: | Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
Evaluation Guideline: | Single sample maximum allowable density for E. coli in freshwater is 235 MPN/100mL (as stated in Table 4, page 15)
Guideline Reference: | Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
Spatial Representation: | Data for this line of evidence for Pacific Ocean at Cowell Beach (Santa Cruz County) was collected at one AB411 monitoring site (Cowell Beach West of the Wharf)
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):
LOE ID: | 19529
Pollutant: | Escherichia coli (E. Coli)
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: | Central Coast Regional Board Staff assessed data for Pacific Ocean at Cowell Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 0 of 7 samples exceed the criterion for Escherichia coli.
Data Reference: | AB 411 Data for 2004
| AB 411 Data for 2005
| AB 411 Data for 2006
Water Quality Objective/Criterion: | USEPA Ambient Water Quality Criteria for Bacteria -1986.
Objective/Criterion Reference: | Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
Evaluation Guideline: | Single sample maximum allowable density for E. coli in freshwater is 235 MPN/100mL (as stated in Table 4, page 15)
Guideline Reference: | Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
Spatial Representation: | Data for this line of evidence for Pacific Ocean at Cowell Beach (Santa Cruz County) was collected at one AB411 monitoring site (Cowell's Beach @ the Stairs)
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):
LOE ID: | 19528
Pollutant: | Escherichia coli (E. Coli)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 2
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 Cowell Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Escherichia coli.
Data Reference: | AB 411 Data for 2004
| AB 411 Data for 2005
| AB 411 Data for 2006
Water Quality Objective/Criterion: | USEPA Ambient Water Quality Criteria for Bacteria -1986.
Objective/Criterion Reference: | Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
Evaluation Guideline: | Steady State Geometric Mean Indicator Density is 126 MPN/100mL (as stated in Table 4, Page 15).
Guideline Reference: | Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
Spatial Representation: | Data for this line of evidence for Pacific Ocean at Cowell Beach (Santa Cruz County) was collected at one AB411 monitoring site (Cowell's Beach @ the Stairs)
Temporal Representation: | Two samples were collected at this site on the following dates: 3/8/2004 and 12/26/2006. These data were submitted as part of the AB411 project.
Environmental Conditions: |
QAPP Information: | QA information not available
QAPP Information Reference(s):

DECISION ID | 10950
Pollutant: | Fecal Coliform
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
Weight of Evidence: | This water segment-pollutant combination is being considered for placement on the 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. Four lines of evidence are available in the administrative record to assess this water segment-pollutant combination. Data were collected from two different locations on Cowell beach. Lines of evidence #19480 and #19500 summarize data from the site west of the wharf and LOEs #19505 and #19506 summarize data from the site at the stairs. Water Board staff assessed the data for each site against two different evaluation criteria (i.e. single sample maximum and geomean). At the site located west of the wharf, 10 of 111 samples exceeded the single sample maximum criterion and 3 of 22 geomean assessments exceeded the geomean criterion. At the monitoring site located at the base of the stairs, 1 of 90 samples exceeded the single sample maximum criterion and 0 of 21 geomean assessments exceeded the geomean criterion. 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 section 303(d) list in the Water Quality Limited Segments category. 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. At the site located west of the wharf, 10 of 111 samples exceeded the single sample maximum criterion and 3 of 22 geomean assessments exceeded the geomean criterion. At the monitoring site located at the base of the stairs, 1 of 90 samples exceeded the single sample maximum criterion and 0 of 21 geomean assessments exceeded the geomean criterion. Neither of these 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.
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 placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10950

LOE ID: | 19480
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 22
Number of Exceedances: | 3
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed data for Pacific Ocean at Cowell Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 3 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
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 Cowell Beach (Santa Cruz County) was collected at one AB411 monitoring site (Cowell Beach West of the Wharf)
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):
LOE ID: | 19500
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 111
Number of Exceedances: | 10
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed data for Pacific Ocean at Cowell Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 10 of 111 samples exceed the criterion for Coliform, Fecal.
Data Reference: | AB 411 Data for 2004
| AB 411 Data for 2005
| AB 411 Data for 2006
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 Cowell Beach (Santa Cruz County) was collected at one AB411 monitoring site (Cowell Beach West of the Wharf)
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):
LOE ID: | 19506
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 90
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 Cowell Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 1 of 90 samples exceed the criterion for Coliform, Fecal.
Data Reference: | AB 411 Data for 2004
| AB 411 Data for 2005
| AB 411 Data for 2006
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 Cowell Beach (Santa Cruz County) was collected at one AB411 monitoring site (Cowell's Beach @ the Stairs)
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):
LOE ID: | 19505
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 21
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 Cowell Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 0 of 21 samples exceed the criterion for Coliform, Fecal.
Data Reference: | AB 411 Data for 2004
| AB 411 Data for 2005
| AB 411 Data for 2006
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 Cowell Beach (Santa Cruz County) was collected at one AB411 monitoring site (Cowell's Beach @ the Stairs)
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 | 10951
Pollutant: | Total Coliform
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
Weight of Evidence: | This water segment-pollutant combination is being considered for placement on the 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. Six lines of evidence are available in the administrative record to assess this water segment-pollutant combination. Data was collected from two different locations on Cowell beach. Lines of evidence #19530, ##19531 and #19532 summarize data collected at the site west of the wharf and LOEs #19533, #19534 and #19554 summarize data collected at the site at the stairs. Water Board staff assessed one data set against three different evaluation criteria (i.e. single sample maximum, geomean, and total to fecal ratio). At the site located west of the wharf, 0 of 133 samples exceeded the single sample maximum criterion, 0 of 26 geomean assessments exceeded the geomean criterion, and 1 of 110 sample ratios exceeded the total to fecal ratio criterion. At the monitoring site located at the base of the stairs, 0 of 113 samples exceeded the single sample maximum criterion, 0 of 26 geomean assessments exceeded the geomean criterion, and 0 of 90 sample ratios exceeded the total to fecal ratio criterion. 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 section 303(d) list in the Water Quality Limited Segments category. 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. At the site located west of the wharf, 0 of 133 samples exceeded the single sample maximum criterion, 0 of 26 geomean assessments exceeded the geomean criterion, and 1 of 110 sample ratios exceeded the total to fecal ratio criterion. At the monitoring site located at the base of the stairs, 0 of 113 samples exceeded the single sample maximum criterion, 0 of 26 geomean assessments exceeded the geomean criterion, and 0 of 90 sample ratios exceeded the total to fecal ratio criterion. None of these 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.
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 placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10951

LOE ID: | 19534
Pollutant: | Total Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 26
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 Cowell Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 0 of 26 samples exceed the criterion for Coliform, Total.
Data Reference: | AB 411 Data for 2004
| AB 411 Data for 2005
| AB 411 Data for 2006
Water Quality Objective/Criterion: | California Ocean Plan (2005) 30-day geometric mean standard for total coliform states that total coliform density shall not exceed 1,000 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 Cowell Beach (Santa Cruz County) was collected at one monitoring site (Cowell's Beach @ the Stairs)
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):
LOE ID: | 19530
Pollutant: | Total Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 133
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 Cowell Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 0 of 133 samples exceed the criterion for Coliform, Total.
Data Reference: | AB 411 Data for 2004
| AB 411 Data for 2005
| AB 411 Data for 2006
Water Quality Objective/Criterion: | California Ocean Plan (2005) single sample maximum states that total coliform density shall not exceed 10,000 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 Cowell Beach (Santa Cruz County) was collected at one monitoring site (Cowell Beach West of the Wharf)
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):
LOE ID: | 19532
Pollutant: | Total Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 110
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 Cowell Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 1 of 110 samples exceed the criterion for Coliform, Total.
Data Reference: | AB 411 Data for 2004
| AB 411 Data for 2005
| AB 411 Data for 2006
Water Quality Objective/Criterion: | California Ocean Plan (2005) single sample maximum standard for total coliform states that total coliform density shall not exceed 1,000 MPN/100 mL when the fecal coliform/total coliform ratio exceeds 0.1.
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 Cowell Beach (Santa Cruz County) was collected at one monitoring site (Cowell Beach West of the Wharf)
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):
LOE ID: | 19554
Pollutant: | Total Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 90
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 Cowell Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 0 of 90 samples exceed the criterion for Coliform, Total.
Data Reference: | AB 411 Data for 2004
| AB 411 Data for 2005
| AB 411 Data for 2006
Water Quality Objective/Criterion: | California Ocean Plan (2005) single sample maximum standard for total coliform states that total coliform density shall not exceed 1,000 MPN/100 mL when the fecal coliform/total coliform ratio exceeds 0.1.
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 Cowell Beach (Santa Cruz County) was collected at one monitoring site (Cowell's Beach @ the Stairs)
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):
LOE ID: | 19531
Pollutant: | Total Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 26
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 Cowell Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 0 of 26 samples exceed the criterion for Coliform, Total.
Data Reference: | AB 411 Data for 2004
| AB 411 Data for 2005
| AB 411 Data for 2006
Water Quality Objective/Criterion: | California Ocean Plan (2005) 30-day geometric mean standard for total coliform states that total coliform density shall not exceed 1,000 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 Cowell Beach (Santa Cruz County) was collected at one monitoring site (Cowell Beach West of the Wharf)
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):
LOE ID: | 19533
Pollutant: | Total Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 113
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 Cowell Beach (Santa Cruz County) to determine beneficial use support and results are as follows: 0 of 113 samples exceed the criterion for Coliform, Total.
Data Reference: | AB 411 Data for 2004
| AB 411 Data for 2005
| AB 411 Data for 2006
Water Quality Objective/Criterion: | California Ocean Plan (2005) single sample maximum states that total coliform density shall not exceed 10,000 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 Cowell Beach (Santa Cruz County) was collected at one monitoring site (Cowell's Beach @ the Stairs)
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):