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

# Supporting Information

## Regional Board 3 - Central Coast Region

Water Body Name: | Elkhorn Slough
Water Body ID: | CAE3060001419981209073137
Water Body Type: | Estuary

DECISION ID | 5989
Pollutant: | Pathogens
Final Listing Decision: | Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2006)
Revision Status | Revised
Reason for Delisting: | Change from general pollutant to specific pollutant listing (e.g. metals to copper)
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for removal from the section 303(d) list under section 4.2 of the Listing Policy. Under section 4.2 a single line of evidence is necessary to assess listing status. No data is contained in this listing. This listing is a general listing for Pathogens. It is not possible, in a general listing, to determine which specific pollutant is causing or contributing to a water quality impacts. There is sufficient justification for removing the general listing for Pathogens from the 303(d) list and replace this general listing with decisions for each of the specific pollutants that apply. This Decision is replaced by Decision #13097, which lists Elkhorn Slough for exceedance of the Shellfish Beneficial Use. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of removing this water segment-pollutant combination from the section 303(d) list.
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 it cannot be determined if applicable water quality standards are being exceeded.
SWRCB Board Decision / Staff Recommendation: | N/A
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 5989

LOE ID: | 3942
Pollutant: | Pathogens
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Not Recorded
Beneficial Use: | Water Contact Recreation
Number of Samples: | 0
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: | Placeholder reference pre-2006 303(d)
Water Quality Objective/Criterion: | Unspecified
Objective/Criterion Reference: | Placeholder reference pre-2006 303(d)
Evaluation Guideline: | Unspecified
Guideline Reference: | Placeholder reference pre-2006 303(d)
Spatial Representation: | Unspecified
Temporal Representation: | Unspecified
Environmental Conditions: | Unspecified
QAPP Information: | Unspecified
QAPP Information Reference(s):

DECISION ID | 13110
Pollutant: | Ammonia (Unionized)
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 pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 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. None of the 12 samples exceed the water quality objectives for Warm or Cold Freshwater Habitat. 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 16 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 12 samples exceed the water quality objectives for Warm or Cold Freshwater Habitat and this does not exceed the allowable frequency listed in Table 3.1 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 13110

LOE ID: | 9386
Pollutant: | Ammonia (Unionized)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Ammonia as N, Unionized.
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin General Objective, Chapter III, Section II.A.2 (General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries) states that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/l (as N) in receiving waters (page III-4) .
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 1/23/2006-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 9387
Pollutant: | Ammonia (Unionized)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Ammonia as N, Unionized.
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin General Objective, Chapter III, Section II.A.2 (General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries) states that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/l (as N) in receiving waters (page III-4) .
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 1/23/2006-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 13114
Pollutant: | Chlorophyll-a
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 pollutant is being considered for placement on the 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. Twenty-nine of the 302 samples exceed the Evaluation Guideline (North Carolina Administrative code, Title 15A) and the General Water Quality Objective set to protect aquatic life beneficial uses. 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. Twenty-nine of the 302 samples exceed the Evaluation Guideline (North Carolina Administrative code, Title 15A) and the General Water Quality Objective set to protect aquatic life beneficial uses 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.
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 13114

LOE ID: | 9383
Pollutant: | Chlorophyll-a
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 25
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 1 of 25 samples exceed the criterion for Chlorophyll a.
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| Water quality standards table
Evaluation Guideline: | North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference: | North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 3/29/1999-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 9384
Pollutant: | Chlorophyll-a
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 25
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 1 of 25 samples exceed the criterion for Chlorophyll a.
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| Water quality standards table
Evaluation Guideline: | North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference: | North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 3/29/1999-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 15223
Pollutant: | Chlorophyll-a
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 277
Number of Exceedances: | 28
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed National Estuarine Research Reserve Monitoring Program (R3_ESNERR) data for Elkhorn Slough to determine beneficial use support and results are as follows: 28 of 277 samples exceed the criterion for Chlorophyll a.
Data Reference: | Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Field Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 94-04
Water Quality Objective/Criterion: | Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| Water quality standards table
Evaluation Guideline: | North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference: | North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 11 monitoring sites [ 306ELKRBR - Reserve Bridge, 306ELKSTB - Strawberry Rd, 306ELKKPD - Kirby Park, 306ELKAPC - Azevedo Pond, Central, 306ELKRSM - Reserve, South Marsh, 306ELKAPS - Azevedo Pond, South, 306ELKHLW - Hudson's Landing West, 306ELKAPN - Azevedo Pond, North, 306ELKHLE - Hudson's Landing East, 306ELKCAT - Cattail Swale, 306ELKROK - Rookery Pond]
Temporal Representation: | Data was collected over the time period 7/31/2001-10/10/2006.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | QAPP was adopted for work conducted since 2005. Prior to 2005 no QAPP was in place and data entry was completed by volunteers. Multiple errors were identified in data and were flagged by RB staff (in communication with Elkhorn Slough Program staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 15209
Pollutant: | Chlorophyll-a
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 277
Number of Exceedances: | 28
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed National Estuarine Research Reserve Monitoring Program (R3_ESNERR) data for Elkhorn Slough to determine beneficial use support and results are as follows: 28 of 277 samples exceed the criterion for Chlorophyll a.
Data Reference: | Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Field Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 94-04
Water Quality Objective/Criterion: | Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (general objective for biostimulatory substances, Water Quality Control Plan, Central Coast Basin, Chapter III, Section II).
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| Water quality standards table
Evaluation Guideline: | North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference: | North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
| North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 11 monitoring sites [ 306ELKRBR - Reserve Bridge, 306ELKSTB - Strawberry Rd, 306ELKKPD - Kirby Park, 306ELKAPC - Azevedo Pond, Central, 306ELKRSM - Reserve, South Marsh, 306ELKAPS - Azevedo Pond, South, 306ELKHLW - Hudson's Landing West, 306ELKAPN - Azevedo Pond, North, 306ELKHLE - Hudson's Landing East, 306ELKCAT - Cattail Swale, 306ELKROK - Rookery Pond]
Temporal Representation: | Data was collected over the time period 7/31/2001-10/10/2006.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | QAPP was adopted for work conducted since 2005. Prior to 2005 no QAPP was in place and data entry was completed by volunteers. Multiple errors were identified in data and were flagged by RB staff (in communication with Elkhorn Slough Program staff) prior to assessment of data.
QAPP Information Reference(s):

DECISION ID | 13091
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 pollutant 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. Two lines of evidence are available in the administrative record to assess this pollutant. One of the 44 samples exceed the water quality objective for Water Contact but none of the samples exceed the Non-Contact Recreation Basin Plan Objective for Fecal Coliform as it is applies to the Enterococcus data. 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. One of the 44 samples exceed the water quality objective for Water Contact but none of the samples exceed the Non-Contact Recreation Basin Plan Objective for Fecal Coliform as it is applies to the Enterococcus data. 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 13091

LOE ID: | 14215
Pollutant: | Enterococcus
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Non-Contact Recreation
Number of Samples: | 44
Number of Exceedances: | 0
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed Central Coast Long Term Environmental Assessment Program (R3_CCLEAN) data for Elkhorn Slough to determine beneficial use support and results are as follows: 0 of 44 samples exceed the criterion for Enterococci.
Data Reference: | Final Data File used for assessment: CCLEAN (Central Coast Long Term Environmental Assessment Program data) Water Quality Data
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 2000/100 ml, nor shall more than ten percent of samples collected during any 30-day period exceed 4000/100 ml. Enterococcus is a fecal coliform.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 2 monitoring sites [ 308ELK_CCL - Elkhorn Slough at N. Kirkby Park, 306ELJ_CCL - Elkhorn Slough at N. Jetty]
Temporal Representation: | Data was collected over the time period 1/22/2002-12/2/2003.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | EPA Approved QAPP.
QAPP Information Reference(s):
LOE ID: | 14214
Pollutant: | Enterococcus
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 44
Number of Exceedances: | 1
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed Central Coast Long Term Environmental Assessment Program (R3_CCLEAN) data for Elkhorn Slough to determine beneficial use support and results are as follows: 1 of 44 samples exceed the EPA criterion for Enterococci.
Data Reference: | Final Data File used for assessment: CCLEAN (Central Coast Long Term Environmental Assessment Program data) Water Quality Data
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 Enterococci in freshwater is 61 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 Elkhorn Slough was collected at 2 monitoring sites [ 308ELK_CCL - Elkhorn Slough at N. Kirkby Park, 306ELJ_CCL - Elkhorn Slough at N. Jetty].
Temporal Representation: | Data was collected monthly over the time period 1/22/2002-12/2/2003.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | EPA Approved QAPP.
QAPP Information Reference(s):

DECISION ID | 13089
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 pollutant 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 pollutant. Ten of the 71 samples exceed the Evaluation Guideline (USEPA Ambient Water Quality Criteria for Bacteria, 1986) as it applies to the Water Contact Recreation beneficial use. None of the 71 samples exceed the water quality objective for Non-Contact Recreation. 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. Ten of the 71 samples exceed the Evaluation Guideline (USEPA Ambient Water Quality Criteria for Bacteria, 1986) as it applies to the Water Contact Recreation beneficial use. None of the 71 samples exceed the water quality objective for Non-Contact Recreation. These do 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 13089

LOE ID: | 18420
Pollutant: | Escherichia coli (E. Coli)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 15
Number of Exceedances: | 7
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Elkhorn Slough to determine beneficial use support and results are as follows: 7 of 15 samples exceed the criterion for Escherichia coli.
Data Reference: | Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
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 Elkhorn Slough was collected at 4 monitoring sites [ 306-ELKHO-34 - Elkhorn Slough, 306-ELKHO-32 - Elkhorn Slough Hudson's Landing, 306-ELKHO-33 - Elkhorn Slough South Marsh Bridge, 306-ELKHO-31 - Elkhorn Slough Kirby Park]
Temporal Representation: | Data was collected over the time period 5/17/2003-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 11168
Pollutant: | Escherichia coli (E. Coli)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Non-Contact Recreation
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Escherichia coli.
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 2000/100 ml, nor shall more than ten percent of samples collected during any 30-day period exceed 4000/100 ml. E. coli is a fecal coliform.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 1/23/2006-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 14071
Pollutant: | Escherichia coli (E. Coli)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Non-Contact Recreation
Number of Samples: | 44
Number of Exceedances: | 0
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed Central Coast Long Term Environmental Assessment Program (R3_CCLEAN) data for Elkhorn Slough to determine beneficial use support and results are as follows: 0 of 44 samples exceed the criterion for Escherichia coli.
Data Reference: | Final Data File used for assessment: CCLEAN (Central Coast Long Term Environmental Assessment Program data) Water Quality Data
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 2000/100 ml, nor shall more than ten percent of samples collected during any 30-day period exceed 4000/100 ml. E. coli is a fecal coliform.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 2 monitoring sites [ 308ELK_CCL - Elkhorn Slough at N. Kirkby Park, 306ELJ_CCL - Elkhorn Slough at N. Jetty]
Temporal Representation: | Data was collected over the time period 1/22/2002-12/2/2003.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | EPA Approved QAPP.
QAPP Information Reference(s):
LOE ID: | 11167
Pollutant: | Escherichia coli (E. Coli)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 12
Number of Exceedances: | 3
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 3 of 12 samples exceed the criterion for Escherichia coli.
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
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 Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 1/23/2006-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 14070
Pollutant: | Escherichia coli (E. Coli)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 44
Number of Exceedances: | 0
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed Central Coast Long Term Environmental Assessment Program (R3_CCLEAN) data for Elkhorn Slough to determine beneficial use support and results are as follows: 0 of 44 samples exceed the criterion for Escherichia coli.
Data Reference: | Final Data File used for assessment: CCLEAN (Central Coast Long Term Environmental Assessment Program data) Water Quality Data
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 Elkhorn Slough was collected at 2 monitoring sites [ 308ELK_CCL - Elkhorn Slough at N. Kirkby Park, 306ELJ_CCL - Elkhorn Slough at N. Jetty]
Temporal Representation: | Data was collected over the time period 1/22/2002-12/2/2003.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | EPA Approved QAPP.
QAPP Information Reference(s):
LOE ID: | 18421
Pollutant: | Escherichia coli (E. Coli)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Non-Contact Recreation
Number of Samples: | 15
Number of Exceedances: | 0
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Elkhorn Slough to determine beneficial use support and results are as follows: 0 of 15 samples exceed the criterion for Escherichia coli.
Data Reference: | Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 2000/100 ml, nor shall more than ten percent of samples collected during any 30-day period exceed 4000/100 ml. E. coli is a fecal coliform.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 4 monitoring sites [ 306-ELKHO-34 - Elkhorn Slough, 306-ELKHO-32 - Elkhorn Slough Hudson's Landing, 306-ELKHO-33 - Elkhorn Slough South Marsh Bridge, 306-ELKHO-31 - Elkhorn Slough Kirby Park]
Temporal Representation: | Data was collected over the time period 5/17/2003-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):

DECISION ID | 13093
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 pollutant 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. One line of evidence is available in the administrative record to assess this pollutant. Two of the 19 samples exceed the water quality objective for Water Contact Recreation. None of the 19 samples exceed the water quality objective for Non-Contact Recreation. 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. Two of the 19 samples exceed the water quality objective for Water Contact Recreation. None of the 19 samples exceed the water quality objective for Non-Contact Recreation 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.
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 13093

LOE ID: | 11166
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Non-Contact Recreation
Number of Samples: | 19
Number of Exceedances: | 0
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 0 of 19 samples exceed the criterion for Coliform, Fecal.
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 2000/100 ml, nor shall more than ten percent of samples collected during any 30-day period exceed 4000/100 ml.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 6/1/1999-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 11165
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 19
Number of Exceedances: | 2
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 2 of 19 samples exceed the criterion for Coliform, Fecal.
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin objective for water contact recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 200 MPN/100 ml, nor shall more than ten percent of total samples during any 30-day period exceed 400 MPN/100 ml.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 6/1/1999-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 13126
Pollutant: | Temperature, water
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 pollutant is being considered for placement on the section 303(d) list under sections 2.1 and 3.2 of the Listing Policy. Four lines of evidence are available in the administrative record to assess this pollutant. Based on section 3.2 the site exceeded numeric objectives for conventional pollutants. According to the binomial distribution, waters shall be placed on the section 303(d) list if the number of measured exceedances supports rejection of the null hypothesis as presented in Table 3.2. Four hundred eighteen of 1823 samples exceed the Evaluation Guideline (Moyle 1976) applied to protect the Cold Freshwater Habitat beneficial use. However, Temperature Evaluation Guideline (Moyle 1976) is not relevant for this waterbody because based on the recent publication (Steelhead/Rainbow Trout (Oncorhynchus mykiss) Resources South of the Golden Gate, California (Becker, G.S and I.J Reining, October 2008), steelhead populations have not been documented there. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of 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 Temperature Evaluation Guideline (Moyle 1976) is not relevant for this waterbody as no known steelhead populations have been documented there. 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 the Temperature Evaluation Guideline (Moyle 1976) is not relevant for this waterbody as no known steelhead populations have been documented there.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 13126

LOE ID: | 12967
Pollutant: | Temperature, water
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Elkhorn Slough to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Water Temperature.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses (General Objective in Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).
Guideline Reference: | Inland Fishes of California
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 7/6/1999-10/6/1999. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 18690
Pollutant: | Temperature, water
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 14
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Elkhorn Slough to determine beneficial use support and results are as follows: 1 of 14 samples exceed the criterion for Water Temperature.
Data Reference: | Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion: | Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses (General Objective in Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).
Guideline Reference: | Inland Fishes of California
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 4 monitoring sites [ 306-ELKHO-34 - Elkhorn Slough, 306-ELKHO-32 - Elkhorn Slough Hudson's Landing, 306-ELKHO-33 - Elkhorn Slough South Marsh Bridge, 306-ELKHO-31 - Elkhorn Slough Kirby Park]
Temporal Representation: | Data was collected over the time period 5/17/2003-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 15228
Pollutant: | Temperature, water
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1782
Number of Exceedances: | 416
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed National Estuarine Research Reserve Monitoring Program (R3_ESNERR) data for Elkhorn Slough to determine beneficial use support and results are as follows: 416 of 1782 samples exceed the criterion for Water Temperature.
Data Reference: | Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Field Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 94-04
Water Quality Objective/Criterion: | Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses (General Objective in Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).
Guideline Reference: | Inland Fishes of California
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 12 monitoring sites [ 306ELKAPN - Azevedo Pond, North, 306ELKAPC - Azevedo Pond, Central, 306ELKAPS - Azevedo Pond, South, 306ELKRBR - Reserve Bridge, 306ELKRSM - Reserve, South Marsh, 306ELKSTB - Strawberry Rd, 306ELKRNM - Reserve, North Marsh, 306ELKKPD - Kirby Park, 306ELKHLE - Hudson's Landing East, 306ELKHLW - Hudson's Landing West, 306ELKROK - Rookery Pond, 306ELKCAT - Cattail Swale]
Temporal Representation: | Data was collected over the time period 1/20/1990-10/10/2006.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | QAPP was adopted for work conducted since 2005. Prior to 2005 no QAPP was in place and data entry was completed by volunteers. Multiple errors were identified in data and were flagged by RB staff (in communication with Elkhorn Slough Program staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 12985
Pollutant: | Temperature, water
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 24
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 1 of 24 samples exceed the criterion for Water Temperature.
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses (General Objective in Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).
Guideline Reference: | Inland Fishes of California
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 3/1/1999-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 13127
Pollutant: | Turbidity
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 pollutant is being considered for placement on the section 303(d) list under sections 2.1 and 3.2 of the Listing Policy. Six lines of evidence are available in the administrative record to assess this pollutant. Based on section 3.2 the site exceeded numeric objectives for conventional pollutants. According to the binomial distribution, waters shall be placed on the section 303(d) list if the number of measured exceedances supports rejection of the null hypothesis as presented in Table 3.2. Four hundred thirty-three samples out of 1741 exceed the Evaluation Guideline (Sigler et al., 1984) applied to protect for aquatic life beneficial uses. However, theTurbidity Evaluation Guideline (Sigler et al., 1984) is not relevant for this waterbody because based on the recent publication (Steelhead/Rainbow Trout (Oncorhynchus mykiss) Resources South of the Golden Gate, California (Becker, G.S and I.J Reining, October 2008), steelhead populations have not been documented there. In addition, the Elkhorn Slough is tidally influenced. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of 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 Turbidity Evaluation Guideline (Sigler et al., 1984) is not relevant for this waterbody . 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 the Turbidity Evaluation Guideline (Sigler et al., 1984) is not relevant for this waterbody .
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 13127

LOE ID: | 15261
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1726
Number of Exceedances: | 432
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed National Estuarine Research Reserve Monitoring Program (R3_ESNERR) data for Elkhorn Slough to determine beneficial use support and results are as follows: 432 of 1726 samples exceed the criterion for Turbidity(NTU).
Data Reference: | Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Field Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 94-04
Water Quality Objective/Criterion: | Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference: | Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 12 monitoring sites [ 306ELKAPN - Azevedo Pond, North, 306ELKAPC - Azevedo Pond, Central, 306ELKAPS - Azevedo Pond, South, 306ELKRBR - Reserve Bridge, 306ELKRSM - Reserve, South Marsh, 306ELKSTB - Strawberry Rd, 306ELKRNM - Reserve, North Marsh, 306ELKKPD - Kirby Park, 306ELKHLE - Hudson's Landing East, 306ELKHLW - Hudson's Landing West, 306ELKROK - Rookery Pond, 306ELKCAT - Cattail Swale]
Temporal Representation: | Data was collected over the time period 1/20/1990-10/10/2006.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | QAPP was adopted for work conducted since 2005. Prior to 2005 no QAPP was in place and data entry was completed by volunteers. Multiple errors were identified in data and were flagged by RB staff (in communication with Elkhorn Slough Program staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 18744
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Elkhorn Slough to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Turbidity(NTU).
Data Reference: | Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion: | Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference: | Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 3 monitoring sites [ 306-ELKHO-34 - Elkhorn Slough, 306-ELKHO-32 - Elkhorn Slough Hudson's Landing, 306-ELKHO-33 - Elkhorn Slough South Marsh Bridge]
Temporal Representation: | Data was collected on a single day 5/17/2003. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 12987
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 12
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 1 of 12 samples exceed the criterion for Turbidity(NTU).
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference: | Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 1/23/2006-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12986
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 12
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 1 of 12 samples exceed the criterion for Turbidity(NTU).
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference: | Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 1/23/2006-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 15274
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1726
Number of Exceedances: | 432
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed National Estuarine Research Reserve Monitoring Program (R3_ESNERR) data for Elkhorn Slough to determine beneficial use support and results are as follows: 432 of 1726 samples exceed the criterion for Turbidity(NTU).
Data Reference: | Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Field Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 94-04
Water Quality Objective/Criterion: | Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference: | Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 12 monitoring sites [ 306ELKAPN - Azevedo Pond, North, 306ELKAPC - Azevedo Pond, Central, 306ELKAPS - Azevedo Pond, South, 306ELKRBR - Reserve Bridge, 306ELKRSM - Reserve, South Marsh, 306ELKSTB - Strawberry Rd, 306ELKRNM - Reserve, North Marsh, 306ELKKPD - Kirby Park, 306ELKHLE - Hudson's Landing East, 306ELKHLW - Hudson's Landing West, 306ELKROK - Rookery Pond, 306ELKCAT - Cattail Swale]
Temporal Representation: | Data was collected over the time period 1/20/1990-10/10/2006.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | QAPP was adopted for work conducted since 2005. Prior to 2005 no QAPP was in place and data entry was completed by volunteers. Multiple errors were identified in data and were flagged by RB staff (in communication with Elkhorn Slough Program staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 18745
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Elkhorn Slough to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Turbidity(NTU).
Data Reference: | Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion: | Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: | Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.
Guideline Reference: | Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 3 monitoring sites [ 306-ELKHO-34 - Elkhorn Slough, 306-ELKHO-32 - Elkhorn Slough Hudson's Landing, 306-ELKHO-33 - Elkhorn Slough South Marsh Bridge]
Temporal Representation: | Data was collected on a single day 5/17/2003. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):

DECISION ID | 13120
Pollutant: | Low Dissolved Oxygen
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Sources: | Agriculture | Grazing-Related Sources | Natural Sources | Urban Runoff/Storm Sewers
Expected TMDL Completion Date: | 2021
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under sections 2.1 and 3.2 of the Listing Policy. Eighteen lines of evidence are available in the administrative record to assess these pollutants. Three beneficial uses are assessed: 631 of the 1596 samples exceed the dissolved oxygen water quality objective for Cold Freshwater Habitat, 274 of 1596 exceed the dissolved oxygen water quality objective for Warm Freshwater Habitat, and 407 of 1004 samples exceed the general water quality objective for oxygen saturation (applied as a single sample maximum). However, the Basin Plan objective states that the median oxygen saturation value shall not fall below 85% and the median value did not exceed this criterion. Therefore, the use rating for oxygen saturation is set at Insufficient Information. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of 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. A total of 631 of the 1596 samples exceed the dissolved oxygen water quality objective for Cold Freshwater Habitat, and 274 of 1596 exceed the dissolved oxygen water quality objective for Warm Freshwater Habitat. 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 be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 13120

LOE ID: | 12969
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Marine Habitat
Aquatic Life Use: | Marine Habitat
Number of Samples: | 24
Number of Exceedances: | 11
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 11 of 24 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin, Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a states the following: Waters shall not contain concentrations of chemical constituents known to be deleterious to fish or wildlife in excess of limits listed in Table 3-6 (page III-12). Table 3-6 states that the Marine Habitat Objective for dissolved oxygen states that the concentration shall not be reduced below 7.0 mg/l at any time.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 3/1/1999-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12968
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 24
Number of Exceedances: | 11
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 11 of 24 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin, Cold Water Habitat Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 3/1/1999-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12089
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 24
Number of Exceedances: | 13
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 13 of 24 samples exceed the criterion for Oxygen, Saturation.
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 3/1/1999-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 18060
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 15
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Elkhorn Slough to determine beneficial use support and results are as follows: 1 of 15 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: | Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 4 monitoring sites [ 306-ELKHO-34 - Elkhorn Slough, 306-ELKHO-32 - Elkhorn Slough Hudson's Landing, 306-ELKHO-33 - Elkhorn Slough South Marsh Bridge, 306-ELKHO-31 - Elkhorn Slough Kirby Park]
Temporal Representation: | Data was collected over the time period 5/17/2003-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 18059
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Marine Habitat
Aquatic Life Use: | Marine Habitat
Number of Samples: | 15
Number of Exceedances: | 4
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Elkhorn Slough to determine beneficial use support and results are as follows: 4 of 15 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: | Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin, Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a states the following: Waters shall not contain concentrations of chemical constituents known to be deleterious to fish or wildlife in excess of limits listed in Table 3-6 (page III-12). Table 3-6 states that the Marine Habitat Objective for dissolved oxygen states that the concentration shall not be reduced below 7.0 mg/l at any time.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 4 monitoring sites [ 306-ELKHO-34 - Elkhorn Slough, 306-ELKHO-32 - Elkhorn Slough Hudson's Landing, 306-ELKHO-33 - Elkhorn Slough South Marsh Bridge, 306-ELKHO-31 - Elkhorn Slough Kirby Park]
Temporal Representation: | Data was collected over the time period 5/17/2003-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 18058
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 15
Number of Exceedances: | 4
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Elkhorn Slough to determine beneficial use support and results are as follows: 4 of 15 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: | Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin, Cold Water Habitat Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 4 monitoring sites [ 306-ELKHO-34 - Elkhorn Slough, 306-ELKHO-32 - Elkhorn Slough Hudson's Landing, 306-ELKHO-33 - Elkhorn Slough South Marsh Bridge, 306-ELKHO-31 - Elkhorn Slough Kirby Park]
Temporal Representation: | Data was collected over the time period 5/17/2003-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 12966
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 2
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Elkhorn Slough to determine beneficial use support and results are as follows: 2 of 3 samples exceed the criterion for Oxygen, Saturation.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 7/6/1999-10/6/1999. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12965
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 2
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Elkhorn Slough to determine beneficial use support and results are as follows: 2 of 3 samples exceed the criterion for Oxygen, Saturation.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 7/6/1999-10/6/1999. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12950
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Elkhorn Slough to determine beneficial use support and results are as follows: 1 of 3 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 7/6/1999-10/6/1999. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12949
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Marine Habitat
Aquatic Life Use: | Marine Habitat
Number of Samples: | 3
Number of Exceedances: | 2
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Elkhorn Slough to determine beneficial use support and results are as follows: 2 of 3 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin, Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a states the following: Waters shall not contain concentrations of chemical constituents known to be deleterious to fish or wildlife in excess of limits listed in Table 3-6 (page III-12). Table 3-6 states that the Marine Habitat Objective for dissolved oxygen states that the concentration shall not be reduced below 7.0 mg/l at any time.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 7/6/1999-10/6/1999. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12948
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 2
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Diurnal Dissolved Oxygen Sampling (DO) data for Elkhorn Slough to determine beneficial use support and results are as follows: 2 of 3 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: | Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin, Cold Water Habitat Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 7/6/1999-10/6/1999. Diurnal monitoring conducted in summer months at all CCAMP monitoring sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12984
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 24
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 1 of 24 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 3/1/1999-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 12074
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 24
Number of Exceedances: | 13
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 13 of 24 samples exceed the criterion for Oxygen, Saturation.
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 3/1/1999-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 15344
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 977
Number of Exceedances: | 392
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed National Estuarine Research Reserve Monitoring Program (R3_ESNERR) data for Elkhorn Slough to determine beneficial use support and results are as follows: 392 of 977 samples exceed the criterion for Oxygen, Saturation.
Data Reference: | Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Field Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 94-04
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 12 monitoring sites [ 306ELKAPN - Azevedo Pond, North, 306ELKAPC - Azevedo Pond, Central, 306ELKAPS - Azevedo Pond, South, 306ELKRBR - Reserve Bridge, 306ELKRSM - Reserve, South Marsh, 306ELKSTB - Strawberry Rd, 306ELKRNM - Reserve, North Marsh, 306ELKKPD - Kirby Park, 306ELKHLE - Hudson's Landing East, 306ELKHLW - Hudson's Landing West, 306ELKROK - Rookery Pond, 306ELKCAT - Cattail Swale]
Temporal Representation: | Data was collected over the time period 11/18/1996-10/10/2006.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | QAPP was adopted for work conducted since 2005. Prior to 2005 no QAPP was in place and data entry was completed by volunteers. Multiple errors were identified in data and were flagged by RB staff (in communication with Elkhorn Slough Program staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 15288
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1554
Number of Exceedances: | 614
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed National Estuarine Research Reserve Monitoring Program (R3_ESNERR) data for Elkhorn Slough to determine beneficial use support and results are as follows: 614 of 1554 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: | Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Field Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 94-04
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin, Cold Water Habitat Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 12 monitoring sites [ 306ELKAPN - Azevedo Pond, North, 306ELKRBR - Reserve Bridge, 306ELKRSM - Reserve, South Marsh, 306ELKSTB - Strawberry Rd, 306ELKRNM - Reserve, North Marsh, 306ELKKPD - Kirby Park, 306ELKAPC - Azevedo Pond, Central, 306ELKAPS - Azevedo Pond, South, 306ELKHLE - Hudson's Landing East, 306ELKHLW - Hudson's Landing West, 306ELKROK - Rookery Pond, 306ELKCAT - Cattail Swale]
Temporal Representation: | Data was collected over the time period 1/20/1990-10/10/2006.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | QAPP was adopted for work conducted since 2005. Prior to 2005 no QAPP was in place and data entry was completed by volunteers. Multiple errors were identified in data and were flagged by RB staff (in communication with Elkhorn Slough Program staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 15289
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Marine Habitat
Aquatic Life Use: | Marine Habitat
Number of Samples: | 1554
Number of Exceedances: | 614
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed National Estuarine Research Reserve Monitoring Program (R3_ESNERR) data for Elkhorn Slough to determine beneficial use support and results are as follows: 614 of 1554 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: | Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Field Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 94-04
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin, Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a states the following: Waters shall not contain concentrations of chemical constituents known to be deleterious to fish or wildlife in excess of limits listed in Table 3-6 (page III-12). Table 3-6 states that the Marine Habitat Objective for dissolved oxygen states that the concentration shall not be reduced below 7.0 mg/l at any time.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 12 monitoring sites [ 306ELKAPN - Azevedo Pond, North, 306ELKRBR - Reserve Bridge, 306ELKRSM - Reserve, South Marsh, 306ELKSTB - Strawberry Rd, 306ELKRNM - Reserve, North Marsh, 306ELKKPD - Kirby Park, 306ELKAPC - Azevedo Pond, Central, 306ELKAPS - Azevedo Pond, South, 306ELKHLE - Hudson's Landing East, 306ELKHLW - Hudson's Landing West, 306ELKROK - Rookery Pond, 306ELKCAT - Cattail Swale]
Temporal Representation: | Data was collected over the time period 1/20/1990-10/10/2006.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | QAPP was adopted for work conducted since 2005. Prior to 2005 no QAPP was in place and data entry was completed by volunteers. Multiple errors were identified in data and were flagged by RB staff (in communication with Elkhorn Slough Program staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 15290
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1554
Number of Exceedances: | 271
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed National Estuarine Research Reserve Monitoring Program (R3_ESNERR) data for Elkhorn Slough to determine beneficial use support and results are as follows: 271 of 1554 samples exceed the criterion for Oxygen, Dissolved.
Data Reference: | Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Field Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 94-04
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 12 monitoring sites [ 306ELKAPN - Azevedo Pond, North, 306ELKRBR - Reserve Bridge, 306ELKRSM - Reserve, South Marsh, 306ELKSTB - Strawberry Rd, 306ELKRNM - Reserve, North Marsh, 306ELKKPD - Kirby Park, 306ELKAPC - Azevedo Pond, Central, 306ELKAPS - Azevedo Pond, South, 306ELKHLE - Hudson's Landing East, 306ELKHLW - Hudson's Landing West, 306ELKROK - Rookery Pond, 306ELKCAT - Cattail Swale]
Temporal Representation: | Data was collected over the time period 1/20/1990-10/10/2006.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | QAPP was adopted for work conducted since 2005. Prior to 2005 no QAPP was in place and data entry was completed by volunteers. Multiple errors were identified in data and were flagged by RB staff (in communication with Elkhorn Slough Program staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 15343
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 977
Number of Exceedances: | 392
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed National Estuarine Research Reserve Monitoring Program (R3_ESNERR) data for Elkhorn Slough to determine beneficial use support and results are as follows: 392 of 977 samples exceed the criterion for Oxygen, Saturation.
Data Reference: | Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Field Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 94-04
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: Median values should not fall below 85% saturation as a result of controllable water quality conditions.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 12 monitoring sites [ 306ELKAPN - Azevedo Pond, North, 306ELKAPC - Azevedo Pond, Central, 306ELKAPS - Azevedo Pond, South, 306ELKRBR - Reserve Bridge, 306ELKRSM - Reserve, South Marsh, 306ELKSTB - Strawberry Rd, 306ELKRNM - Reserve, North Marsh, 306ELKKPD - Kirby Park, 306ELKHLE - Hudson's Landing East, 306ELKHLW - Hudson's Landing West, 306ELKROK - Rookery Pond, 306ELKCAT - Cattail Swale]
Temporal Representation: | Data was collected over the time period 11/18/1996-10/10/2006.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | QAPP was adopted for work conducted since 2005. Prior to 2005 no QAPP was in place and data entry was completed by volunteers. Multiple errors were identified in data and were flagged by RB staff (in communication with Elkhorn Slough Program staff) prior to assessment of data.
QAPP Information Reference(s):

DECISION ID | 13097
Pollutant: | Total Coliform
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Sources: | Source Unknown
Expected TMDL Completion Date: | 2021
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under sections 2.1 and 3.2 of the Listing Policy. In Decision #5989, Elkhorn Slough was delisted for "Pathogens" because of the lack of specificity of that listing and the lack of associated data in the database. Three lines of evidence are available in the administrative record to assess this pollutant. Based on section 3.3 the site exceeded numeric objectives for conventional pollutants. According to the binomial distribution, waters shall be placed on the section 303(d) list if the number of measured exceedances supports rejection of the null hypothesis as presented in Table 3.2. Thirty-two of 90 samples exceed the water quality objective for Shellfishing. This supports rejection of the null hypothesis. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of 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. Thirty-two of 90 samples exceed the water quality objective for Shellfishing and this exceeds 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 be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 13097

LOE ID: | 17441
Pollutant: | Total Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Shellfish Harvesting
Number of Samples: | 15
Number of Exceedances: | 14
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Elkhorn Slough to determine beneficial use support and results are as follows: 14 of 15 samples exceed the criterion for Coliform, Total.
Data Reference: | Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin Shellfish Harvesting objective (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries (page III-12)) states the following: At all areas where shellfish may be harvested for human consumption, the median total coliform concentration throughout the water column for any 30-day period shall not exceed 70 MPN/100mL, not shall more than ten percent of the samples collected during any 30-day period exceed 230 MPN/100mL for a five tube decimal dilution test.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 4 monitoring sites [ 306-ELKHO-34 - Elkhorn Slough, 306-ELKHO-32 - Elkhorn Slough Hudson's Landing, 306-ELKHO-33 - Elkhorn Slough South Marsh Bridge, 306-ELKHO-31 - Elkhorn Slough Kirby Park]
Temporal Representation: | Data was collected over the time period 5/17/2003-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 9385
Pollutant: | Total Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Shellfish Harvesting
Number of Samples: | 31
Number of Exceedances: | 15
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 15 of 31 samples exceed the criterion for Coliform, Total.
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin Shellfish Harvesting objective (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries (page III-12)) states the following: At all areas where shellfish may be harvested for human consumption, the median total coliform concentration throughout the water column for any 30-day period shall not exceed 70 MPN/100mL, not shall more than ten percent of the samples collected during any 30-day period exceed 230 MPN/100mL for a five tube decimal dilution test.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 6/1/1999-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 14009
Pollutant: | Total Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Shellfish Harvesting
Number of Samples: | 44
Number of Exceedances: | 3
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed Central Coast Long Term Environmental Assessment Program (R3_CCLEAN) data for Elkhorn Slough to determine beneficial use support and results are as follows: 3 of 44 samples exceed the criterion for Coliform, Total.
Data Reference: | Final Data File used for assessment: CCLEAN (Central Coast Long Term Environmental Assessment Program data) Water Quality Data
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin Shellfish Harvesting objective (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries (page III-12)) states the following: At all areas where shellfish may be harvested for human consumption, the median total coliform concentration throughout the water column for any 30-day period shall not exceed 70 MPN/100mL, not shall more than ten percent of the samples collected during any 30-day period exceed 230 MPN/100mL for a five tube decimal dilution test.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 2 monitoring sites [ 308ELK_CCL - Elkhorn Slough at N. Kirkby Park, 306ELJ_CCL - Elkhorn Slough at N. Jetty]
Temporal Representation: | Data was collected over the time period 1/22/2002-12/2/2003.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | EPA Approved QAPP.
QAPP Information Reference(s):

DECISION ID | 13129
Pollutant: | pH
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Sources: | Agriculture | Grazing-Related Sources | Natural Sources | Urban Runoff/Storm Sewers
Expected TMDL Completion Date: | 2021
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under sections 2.1 and 3.2 of the Listing Policy. Fifteen line of evidence is available in the administrative record to assess this pollutant. Based on section 3.2 the site exceeded numeric objectives for conventional pollutants. According to the binomial distribution, waters shall be placed on the section 303(d) list if the number of measured exceedances supports rejection of the null hypothesis as presented in Table 3.2. Four hundred seventy-six samples of 1722 exceed the water quality objectives for Cold, Warm, and Marine Habitat. Five hundred eighty-three of 1722 samples exceed the Water Contact and Non-Contact Recreation objectives. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of 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. Four hundred seventy-six samples of 1722 exceed the water quality objectives for Cold, Warm, and Marine Habitat. Five hundred eighty-three of 1722 samples exceed the Water Contact and Non-Contact Recreation objectives. 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 be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 13129

LOE ID: | 15136
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 1695
Number of Exceedances: | 475
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed National Estuarine Research Reserve Monitoring Program (R3_ESNERR) data for Elkhorn Slough to determine beneficial use support and results are as follows: 475 of 1695 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Field Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 94-04
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 12 monitoring sites [ 306ELKAPN - Azevedo Pond, North, 306ELKAPC - Azevedo Pond, Central, 306ELKAPS - Azevedo Pond, South, 306ELKRBR - Reserve Bridge, 306ELKRSM - Reserve, South Marsh, 306ELKSTB - Strawberry Rd, 306ELKRNM - Reserve, North Marsh, 306ELKKPD - Kirby Park, 306ELKHLE - Hudson's Landing East, 306ELKHLW - Hudson's Landing West, 306ELKROK - Rookery Pond, 306ELKCAT - Cattail Swale]
Temporal Representation: | Data was collected over the time period 1/20/1990-10/10/2006.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | QAPP was adopted for work conducted since 2005. Prior to 2005 no QAPP was in place and data entry was completed by volunteers. Multiple errors were identified in data and were flagged by RB staff (in communication with Elkhorn Slough Program staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 15121
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Non-Contact Recreation
Number of Samples: | 1695
Number of Exceedances: | 580
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed National Estuarine Research Reserve Monitoring Program (R3_ESNERR) data for Elkhorn Slough to determine beneficial use support and results are as follows: 580 of 1695 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Field Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 94-04
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 12 monitoring sites [ 306ELKAPN - Azevedo Pond, North, 306ELKAPC - Azevedo Pond, Central, 306ELKAPS - Azevedo Pond, South, 306ELKRBR - Reserve Bridge, 306ELKRSM - Reserve, South Marsh, 306ELKSTB - Strawberry Rd, 306ELKRNM - Reserve, North Marsh, 306ELKKPD - Kirby Park, 306ELKHLE - Hudson's Landing East, 306ELKHLW - Hudson's Landing West, 306ELKROK - Rookery Pond, 306ELKCAT - Cattail Swale]
Temporal Representation: | Data was collected over the time period 1/20/1990-10/10/2006.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | QAPP was adopted for work conducted since 2005. Prior to 2005 no QAPP was in place and data entry was completed by volunteers. Multiple errors were identified in data and were flagged by RB staff (in communication with Elkhorn Slough Program staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 15120
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 1695
Number of Exceedances: | 580
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed National Estuarine Research Reserve Monitoring Program (R3_ESNERR) data for Elkhorn Slough to determine beneficial use support and results are as follows: 580 of 1695 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Field Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 94-04
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin objective for water contact recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 12 monitoring sites [ 306ELKAPN - Azevedo Pond, North, 306ELKAPC - Azevedo Pond, Central, 306ELKAPS - Azevedo Pond, South, 306ELKRBR - Reserve Bridge, 306ELKRSM - Reserve, South Marsh, 306ELKSTB - Strawberry Rd, 306ELKRNM - Reserve, North Marsh, 306ELKKPD - Kirby Park, 306ELKHLE - Hudson's Landing East, 306ELKHLW - Hudson's Landing West, 306ELKROK - Rookery Pond, 306ELKCAT - Cattail Swale]
Temporal Representation: | Data was collected over the time period 1/20/1990-10/10/2006.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | QAPP was adopted for work conducted since 2005. Prior to 2005 no QAPP was in place and data entry was completed by volunteers. Multiple errors were identified in data and were flagged by RB staff (in communication with Elkhorn Slough Program staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 15119
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Marine Habitat
Aquatic Life Use: | Marine Habitat
Number of Samples: | 1695
Number of Exceedances: | 475
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed National Estuarine Research Reserve Monitoring Program (R3_ESNERR) data for Elkhorn Slough to determine beneficial use support and results are as follows: 475 of 1695 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Field Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 94-04
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin, Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a states the following for Marine Habitat beneficial uses: The pH value shall not be depressed below 7.0 or raised above 8.5. Changes in normal ambient pH levels shall not exceed 0.2 units.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 12 monitoring sites [ 306ELKAPN - Azevedo Pond, North, 306ELKAPC - Azevedo Pond, Central, 306ELKAPS - Azevedo Pond, South, 306ELKRBR - Reserve Bridge, 306ELKRSM - Reserve, South Marsh, 306ELKSTB - Strawberry Rd, 306ELKRNM - Reserve, North Marsh, 306ELKKPD - Kirby Park, 306ELKHLE - Hudson's Landing East, 306ELKHLW - Hudson's Landing West, 306ELKROK - Rookery Pond, 306ELKCAT - Cattail Swale]
Temporal Representation: | Data was collected over the time period 1/20/1990-10/10/2006.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | QAPP was adopted for work conducted since 2005. Prior to 2005 no QAPP was in place and data entry was completed by volunteers. Multiple errors were identified in data and were flagged by RB staff (in communication with Elkhorn Slough Program staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 15118
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 1695
Number of Exceedances: | 475
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed National Estuarine Research Reserve Monitoring Program (R3_ESNERR) data for Elkhorn Slough to determine beneficial use support and results are as follows: 475 of 1695 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Field Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 2006
| Final Data File used for assessment: ESNERR (Elkhorn Slough National Reserve) Water Quality Data from 94-04
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 12 monitoring sites [ 306ELKAPN - Azevedo Pond, North, 306ELKAPC - Azevedo Pond, Central, 306ELKAPS - Azevedo Pond, South, 306ELKRBR - Reserve Bridge, 306ELKRSM - Reserve, South Marsh, 306ELKSTB - Strawberry Rd, 306ELKRNM - Reserve, North Marsh, 306ELKKPD - Kirby Park, 306ELKHLE - Hudson's Landing East, 306ELKHLW - Hudson's Landing West, 306ELKROK - Rookery Pond, 306ELKCAT - Cattail Swale]
Temporal Representation: | Data was collected over the time period 1/20/1990-10/10/2006.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | QAPP was adopted for work conducted since 2005. Prior to 2005 no QAPP was in place and data entry was completed by volunteers. Multiple errors were identified in data and were flagged by RB staff (in communication with Elkhorn Slough Program staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 19041
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 15
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Elkhorn Slough to determine beneficial use support and results are as follows: 1 of 15 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 4 monitoring sites [ 306-ELKHO-34 - Elkhorn Slough, 306-ELKHO-32 - Elkhorn Slough Hudson's Landing, 306-ELKHO-33 - Elkhorn Slough South Marsh Bridge, 306-ELKHO-31 - Elkhorn Slough Kirby Park]
Temporal Representation: | Data was collected over the time period 5/17/2003-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 19060
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 15
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Elkhorn Slough to determine beneficial use support and results are as follows: 1 of 15 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 4 monitoring sites [ 306-ELKHO-34 - Elkhorn Slough, 306-ELKHO-32 - Elkhorn Slough Hudson's Landing, 306-ELKHO-33 - Elkhorn Slough South Marsh Bridge, 306-ELKHO-31 - Elkhorn Slough Kirby Park]
Temporal Representation: | Data was collected over the time period 5/17/2003-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 19059
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Non-Contact Recreation
Number of Samples: | 15
Number of Exceedances: | 3
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Elkhorn Slough to determine beneficial use support and results are as follows: 3 of 15 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 4 monitoring sites [ 306-ELKHO-34 - Elkhorn Slough, 306-ELKHO-32 - Elkhorn Slough Hudson's Landing, 306-ELKHO-33 - Elkhorn Slough South Marsh Bridge, 306-ELKHO-31 - Elkhorn Slough Kirby Park]
Temporal Representation: | Data was collected over the time period 5/17/2003-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 19057
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Marine Habitat
Aquatic Life Use: | Marine Habitat
Number of Samples: | 15
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Elkhorn Slough to determine beneficial use support and results are as follows: 1 of 15 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin, Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a states the following for Marine Habitat beneficial uses: The pH value shall not be depressed below 7.0 or raised above 8.5. Changes in normal ambient pH levels shall not exceed 0.2 units.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 4 monitoring sites [ 306-ELKHO-34 - Elkhorn Slough, 306-ELKHO-32 - Elkhorn Slough Hudson's Landing, 306-ELKHO-33 - Elkhorn Slough South Marsh Bridge, 306-ELKHO-31 - Elkhorn Slough Kirby Park]
Temporal Representation: | Data was collected over the time period 5/17/2003-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 19058
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 15
Number of Exceedances: | 3
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed Coastal Watershed Council (Snapshot day monitoring) (R3_Snap) data for Elkhorn Slough to determine beneficial use support and results are as follows: 3 of 15 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: Monterey Bay National Marine Sanctuary Volunteer Monitoring Network Data. 2003-2006
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin objective for water contact recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 4 monitoring sites [ 306-ELKHO-34 - Elkhorn Slough, 306-ELKHO-32 - Elkhorn Slough Hudson's Landing, 306-ELKHO-33 - Elkhorn Slough South Marsh Bridge, 306-ELKHO-31 - Elkhorn Slough Kirby Park]
Temporal Representation: | Data was collected over the time period 5/17/2003-5/6/2006. Coastal Watershed Council Snapshot Day Monitoring is conducted annually.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | State Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.
QAPP Information Reference(s):
LOE ID: | 11187
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 1/23/2006-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 11186
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Non-Contact Recreation
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 1/23/2006-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 11185
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin objective for water contact recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 1/23/2006-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 11184
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Marine Habitat
Aquatic Life Use: | Marine Habitat
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | The Water Quality Control Plan, Central Coast Basin, Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a states the following for Marine Habitat beneficial uses: The pH value shall not be depressed below 7.0 or raised above 8.5. Changes in normal ambient pH levels shall not exceed 0.2 units.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 1/23/2006-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):
LOE ID: | 11183
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Central Coast Regional Board Staff assessed CCAMP Salinas (Salinas) data for Elkhorn Slough to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for pH.
Data Reference: | Final Data File used for assessment: CCAMP Salinas Toxicity data
| Final Data File used for assessment: CCAMP Water Quality Data_file1
| Final Data File used for assessment: CCAMP Water Quality Data_file2
| Final Data File used for assessment: CCAMP Water Quality Data_file3
Water Quality Objective/Criterion: | Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.
Objective/Criterion Reference: | Water Quality Control Plan Central Coast Region (R3) Basin Plan
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Elkhorn Slough was collected at 1 monitoring site [ 306ELK-Elkhorn Slough at Kirby Park]
Temporal Representation: | Data was collected over the time period 1/23/2006-12/18/2006. Salinas watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year. Toxicity monitoring is conducted twice during the rotation year (winter and summer) at a subset of sites.
Environmental Conditions: | Staff is not aware of any special conditions that might effect interpretation of the data.
QAPP Information: | All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission. All data are flagged as appropriate.
QAPP Information Reference(s):

DECISION ID | 5990
Pollutant: | Pesticides
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2006)
Revision Status | Original
Sources: | Agricultural Return Flows | Agriculture | Agriculture-storm runoff | Contaminated Sediments | Erosion/Siltation | Irrigated Crop Production | Nonpoint Source
Expected TMDL Completion Date: | 2021
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | 303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed.
RWQCB Board Decision / Staff Recommendation: | No new data were assessed for 2008. The decision has not changed.
SWRCB Board Decision / Staff Recommendation: | N/A
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 5990

LOE ID: | 3943
Pollutant: | Pesticides
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Not Recorded
Beneficial Use: | Estuarine Habitat
Number of Samples: | 0
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: | Placeholder reference pre-2006 303(d)
Water Quality Objective/Criterion: | Unspecified
Objective/Criterion Reference: | Placeholder reference pre-2006 303(d)
Evaluation Guideline: | Unspecified
Guideline Reference: | Placeholder reference pre-2006 303(d)
Spatial Representation: | Unspecified
Temporal Representation: | Unspecified
Environmental Conditions: | Unspecified
QAPP Information: | Unspecified
QAPP Information Reference(s):

DECISION ID | 5991
Pollutant: | Sedimentation/Siltation
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2006)
Revision Status | Original
Sources: | Agriculture | Agriculture-storm runoff | Channel Erosion | Irrigated Crop Production | Nonpoint Source
Expected TMDL Completion Date: | 2021
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | 303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed.
RWQCB Board Decision / Staff Recommendation: | No new data were assessed for 2008. The decision has not changed.
SWRCB Board Decision / Staff Recommendation: | N/A
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 5991

LOE ID: | 3944
Pollutant: | Sedimentation/Siltation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Not Recorded
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 0
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: | Placeholder reference pre-2006 303(d)
Water Quality Objective/Criterion: | Unspecified
Objective/Criterion Reference: | Placeholder reference pre-2006 303(d)
Evaluation Guideline: | Unspecified
Guideline Reference: | Placeholder reference pre-2006 303(d)
Spatial Representation: | Unspecified
Temporal Representation: | Unspecified
Environmental Conditions: | Unspecified
QAPP Information: | Unspecified
QAPP Information Reference(s):