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

# Supporting Information

## Regional Board 3 - Central Coast Region

Water Body Name: | Bennett Slough
Water Body ID: | CAR3060001420080611160605
Water Body Type: | River & Stream

DECISION ID | 11594
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 section 3.2 of the Listing Policy. Under section 3.2 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. 110 of the 904 samples exceed the Evaluation Guideline (Moyle 1976) applied to protect the Cold Freshwater Habitat beneficial use. 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. 110 of the 904 samples exceed the Evaluation Guideline (Moyle 1976) applied to protect the Cold Freshwater Habitat beneficial use 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 11594

LOE ID: | 15242
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: | 904
Number of Exceedances: | 110
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 Bennett Slough to determine beneficial use support and results are as follows: 110 of 904 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 Bennett Slough was collected at 5 monitoring sites [ 306MSLSKL - Skipper's Landing, 305BENSTP - GoMoss Landing, 306BENJTR - Jetty Road, 306BENWH1 - Bennett Slough, West, 306BENEH1 - Bennett Slough, East]
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):

DECISION ID | 11595
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. Two 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. Two Hundred Eighty of 879 samples exceed the Evaluation Guideline (Sigler et al., 1984) applied to protect for aquatic life beneficial uses. The Turbidity 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. Based on the readily available data and information, the weight of evidence indicates that there is insufficient 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 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 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 11595

LOE ID: | 15292
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 879
Number of Exceedances: | 280
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 Bennett Slough to determine beneficial use support and results are as follows: 280 of 879 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 Bennett Slough was collected at 5 monitoring sites [ 306MSLSKL - Skipper's Landing, 305BENSTP - GoMoss Landing, 306BENJTR - Jetty Road, 306BENWH1 - Bennett Slough, West, 306BENEH1 - Bennett Slough, East]
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: | 15277
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 879
Number of Exceedances: | 280
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 Bennett Slough to determine beneficial use support and results are as follows: 280 of 879 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 Bennett Slough was collected at 5 monitoring sites [ 306MSLSKL - Skipper's Landing, 305BENSTP - GoMoss Landing, 306BENJTR - Jetty Road, 306BENWH1 - Bennett Slough, West, 306BENEH1 - Bennett Slough, East]
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):

DECISION ID | 11591
Pollutant: | Chlorophyll-a
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. Two 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. 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-five of 153 samples exceeded the Evaluation Guideline (North Carolina Administrative code, Title 15A) and the General Water Quality Objective set to protect aquatic life beneficial uses 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 11591

LOE ID: | 15224
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: | 153
Number of Exceedances: | 35
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 Bennett Slough to determine beneficial use support and results are as follows: 35 of 153 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 Bennett Slough was collected at 5 monitoring sites [ 306BENEH1 - Bennett Slough, East, 305BENSTP - GoMoss Landing, 306BENWH1 - Bennett Slough, West, 306BENJTR - Jetty Road, 306MSLSKL - Skipper's Landing]
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: | 15225
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: | 153
Number of Exceedances: | 35
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 Bennett Slough to determine beneficial use support and results are as follows: 35 of 153 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 Bennett Slough was collected at 5 monitoring sites [ 306BENEH1 - Bennett Slough, East, 305BENSTP - GoMoss Landing, 306BENWH1 - Bennett Slough, West, 306BENJTR - Jetty Road, 306MSLSKL - Skipper's Landing]
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 | 11593
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: | 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. 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. Three water quality objectives are assessed: 217 out of 794 dissolved oxygen samples exceed the Cold Freshwater Habitat objective and this supports rejection of the null hypothesis. However, only 94 of 794 samples exceed the Warm Freshwater Habitat objective, therefore this beneficial use is fully supported. In addition, 112 of 443 exceed the general water quality objective for oxygen saturation (when 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. Elevated concentrations of suspended chlorophyll a in Bennett Slough confirm biostimulation and eutrophic conditions. 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 217 out of 794 samples exceed the Cold Freshwater Habitat objective and this supports rejection of the null hypothesis and this meets or 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 11593

LOE ID: | 15063
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: | 443
Number of Exceedances: | 112
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 Bennett Slough to determine beneficial use support and results are as follows: 112 of 443 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 Bennett Slough was collected at 5 monitoring sites [ 306BENJTR - Jetty Road, 306MSLSKL - Skipper's Landing, 305BENSTP - GoMoss Landing, 306BENWH1 - Bennett Slough, West, 306BENEH1 - Bennett Slough, East]
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: | 15062
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: | 443
Number of Exceedances: | 112
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 Bennett Slough to determine beneficial use support and results are as follows: 112 of 443 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 Bennett Slough was collected at 5 monitoring sites [ 306BENJTR - Jetty Road, 306MSLSKL - Skipper's Landing, 305BENSTP - GoMoss Landing, 306BENWH1 - Bennett Slough, West, 306BENEH1 - Bennett Slough, East]
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: | 15308
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: | 794
Number of Exceedances: | 94
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 Bennett Slough to determine beneficial use support and results are as follows: 94 of 794 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 Bennett Slough was collected at 5 monitoring sites [ 306MSLSKL - Skipper's Landing, 305BENSTP - GoMoss Landing, 306BENJTR - Jetty Road, 306BENWH1 - Bennett Slough, West, 306BENEH1 - Bennett Slough, East]
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: | 15307
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: | 794
Number of Exceedances: | 217
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 Bennett Slough to determine beneficial use support and results are as follows: 217 of 794 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 Bennett Slough was collected at 5 monitoring sites [ 306MSLSKL - Skipper's Landing, 305BENSTP - GoMoss Landing, 306BENJTR - Jetty Road, 306BENWH1 - Bennett Slough, West, 306BENEH1 - Bennett Slough, East]
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):

DECISION ID | 11597
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: | 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. 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. 297 out of 856 samples exceed the water quality objectives for Warm and Cold Freshwater Habitat. 402 of 856 samples exceed the water quality objectives for Non-Contact and Water Contact Recreation. These rates of exceedance support 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. 297 out of 856 samples exceed the water quality objectives for Warm and Cold Freshwater Habitat. 402 of 856 samples exceed the water quality objectives for Non-Contact and Water Contact Recreation. 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 11597

LOE ID: | 15158
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 856
Number of Exceedances: | 297
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 Bennett Slough to determine beneficial use support and results are as follows: 297 of 856 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 Bennett Slough was collected at 5 monitoring sites [ 306MSLSKL - Skipper's Landing, 305BENSTP - GoMoss Landing, 306BENJTR - Jetty Road, 306BENWH1 - Bennett Slough, West, 306BENEH1 - Bennett Slough, East]
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: | 15157
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Non-Contact Recreation
Number of Samples: | 856
Number of Exceedances: | 402
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 Bennett Slough to determine beneficial use support and results are as follows: 402 of 856 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 Bennett Slough was collected at 5 monitoring sites [ 306MSLSKL - Skipper's Landing, 305BENSTP - GoMoss Landing, 306BENJTR - Jetty Road, 306BENWH1 - Bennett Slough, West, 306BENEH1 - Bennett Slough, East]
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: | 15156
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 856
Number of Exceedances: | 402
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 Bennett Slough to determine beneficial use support and results are as follows: 402 of 856 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 Bennett Slough was collected at 5 monitoring sites [ 306MSLSKL - Skipper's Landing, 305BENSTP - GoMoss Landing, 306BENJTR - Jetty Road, 306BENWH1 - Bennett Slough, West, 306BENEH1 - Bennett Slough, East]
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: | 15155
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 856
Number of Exceedances: | 297
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 Bennett Slough to determine beneficial use support and results are as follows: 297 of 856 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 Bennett Slough was collected at 5 monitoring sites [ 306MSLSKL - Skipper's Landing, 305BENSTP - GoMoss Landing, 306BENJTR - Jetty Road, 306BENWH1 - Bennett Slough, West, 306BENEH1 - Bennett Slough, East]
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):