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

Supporting Information

Regional Board 2 - San Francisco Bay Region

Water Body Name: Guadalupe Slough
Water Body ID: CAR2051000020110829223355
Water Body Type: River & Stream
 
DECISION ID
97412
Region 2     
Guadalupe Slough
 
Pollutant: Arsenic
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 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. Zero of eighteen samples exceed the guideline.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. Zero of eighteen samples exceed the guideline 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.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 97412, Arsenic
Region 2     
Guadalupe Slough
 
LOE ID: 91834
 
Pollutant: Arsenic
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 18
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed SFEI data for Guadalupe Slough to determine beneficial use support and results are as follows: 0 of 18 samples exceed the criterion for Arsenic.
Data Reference: Regional Monitoring Program data, Feb. 1993-Sep. 2008
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in saline water is 0.036 mg/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
Spatial Representation: Data for this line of evidence for Guadalupe Slough was collected at 1 monitoring site [ Sunnyvale - C-1-3]
Temporal Representation: Data was collected over the time period 2/1/1994-2/7/2001.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The 1999 Quality Assurance Project Plan Regional Monitoring Program for Trace Substances was used.
QAPP Information Reference(s): 1999 Quality Assurance Project Plan Regional Monitoring Program for Trace Substances
 
 
DECISION ID
97471
Region 2     
Guadalupe Slough
 
Pollutant: Cadmium
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 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. Zero of eighteen samples exceed the guideline.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. Zero of eighteen samples exceed the guideline 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.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 97471, Cadmium
Region 2     
Guadalupe Slough
 
LOE ID: 91835
 
Pollutant: Cadmium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 18
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed SFEI data for Guadalupe Slough to determine beneficial use support and results are as follows: 0 of 18 samples exceed the criterion for Cadmium.
Data Reference: Regional Monitoring Program data, Feb. 1993-Sep. 2008
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The dissolved cadmium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in saline water is 0.093 mg/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Guadalupe Slough was collected at 1 monitoring site [ Sunnyvale - C-1-3]
Temporal Representation: Data was collected over the time period 2/1/1994-2/7/2001.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The 1999 Quality Assurance Project Plan Regional Monitoring Program for Trace Substances was used.
QAPP Information Reference(s): 1999 Quality Assurance Project Plan Regional Monitoring Program for Trace Substances
 
 
DECISION ID
97472
Region 2     
Guadalupe Slough
 
Pollutant: Chromium
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 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. Zero of sixteen samples exceed the guideline.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. Zero of sixteen samples exceed the guideline 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.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 97472, Chromium
Region 2     
Guadalupe Slough
 
LOE ID: 91836
 
Pollutant: Chromium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 16
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed SFEI data for Guadalupe Slough to determine beneficial use support and results are as follows: 0 of 16 samples exceed the criterion for Chromium.
Data Reference: Regional Monitoring Program data, Feb. 1993-Sep. 2008
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The dissolved chromium (III) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.180 mg/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Guadalupe Slough was collected at 1 monitoring site [ Sunnyvale - C-1-3]
Temporal Representation: Data was collected over the time period 2/1/1994-7/14/1999.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The 1999 Quality Assurance Project Plan Regional Monitoring Program for Trace Substances was used.
QAPP Information Reference(s): 1999 Quality Assurance Project Plan Regional Monitoring Program for Trace Substances
 
 
DECISION ID
97473
Region 2     
Guadalupe Slough
 
Pollutant: Copper
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 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. Zero of twenty-three samples exceed the guideline.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. Zero of twenty-three samples exceed the guideline 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.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 97473, Copper
Region 2     
Guadalupe Slough
 
LOE ID: 91837
 
Pollutant: Copper
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 23
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed SFEI data for Guadalupe Slough to determine beneficial use support and results are as follows: 0 of 23 samples exceed the criterion for Copper.
Data Reference: Regional Monitoring Program data, Feb. 1993-Sep. 2008
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: According to table 3-3A, the Copper site-specific objective for Guadalupe Slough is 6 ug/L.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Guadalupe Slough was collected at 1 monitoring site [ Sunnyvale - C-1-3]
Temporal Representation: Data was collected over the time period 2/1/1994-7/23/2002.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The 1999 Quality Assurance Project Plan Regional Monitoring Program for Trace Substances was used.
QAPP Information Reference(s): 1999 Quality Assurance Project Plan Regional Monitoring Program for Trace Substances
 
 
DECISION ID
100146
Region 2     
Guadalupe Slough
 
Pollutant: Lead
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 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. Zero of eighteen samples exceed the guideline.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. Zero of eighteen samples exceed the guideline 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.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 100146, Lead
Region 2     
Guadalupe Slough
 
LOE ID: 91838
 
Pollutant: Lead
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 18
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed SFEI data for Guadalupe Slough to determine beneficial use support and results are as follows: 0 of 18 samples exceed the criterion for Lead.
Data Reference: Regional Monitoring Program data, Feb. 1993-Sep. 2008
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The dissolved lead criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in saline water is 0.0081 mg/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Guadalupe Slough was collected at 1 monitoring site [ Sunnyvale - C-1-3]
Temporal Representation: Data was collected over the time period 2/1/1994-2/7/2001.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The 1999 Quality Assurance Project Plan Regional Monitoring Program for Trace Substances was used.
QAPP Information Reference(s): 1999 Quality Assurance Project Plan Regional Monitoring Program for Trace Substances
 
 
DECISION ID
97055
Region 2     
Guadalupe Slough
 
Pollutant: Nickel
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 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. Zero of eighteen samples exceed the guideline.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. Zero of eighteen samples exceed the guideline 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.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 97055, Nickel
Region 2     
Guadalupe Slough
 
LOE ID: 91839
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 18
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed SFEI data for Guadalupe Slough to determine beneficial use support and results are as follows: 0 of 18 samples exceed the criterion for Nickel.
Data Reference: Regional Monitoring Program data, Feb. 1993-Sep. 2008
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The dissolved nickel criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in saline water is 0.0082 mg/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Guadalupe Slough was collected at 1 monitoring site [ Sunnyvale - C-1-3]
Temporal Representation: Data was collected over the time period 2/1/1994-2/7/2001.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The 1999 Quality Assurance Project Plan Regional Monitoring Program for Trace Substances was used.
QAPP Information Reference(s): 1999 Quality Assurance Project Plan Regional Monitoring Program for Trace Substances
 
 
DECISION ID
97056
Region 2     
Guadalupe Slough
 
Pollutant: Selenium
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 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. Zero of eighteen samples exceed the guideline.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. Zero of eighteen samples exceed the guideline 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.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 97056, Selenium
Region 2     
Guadalupe Slough
 
LOE ID: 91840
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 18
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed SFEI data for Guadalupe Slough to determine beneficial use support and results are as follows: 0 of 18 samples exceed the criterion for Selenium.
Data Reference: Regional Monitoring Program data, Feb. 1993-Sep. 2008
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The dissolved selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in saline water is 5 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Guadalupe Slough was collected at 1 monitoring site [ Sunnyvale - C-1-3]
Temporal Representation: Data was collected over the time period 2/1/1994-2/7/2001.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The 1999 Quality Assurance Project Plan Regional Monitoring Program for Trace Substances was used.
QAPP Information Reference(s): 1999 Quality Assurance Project Plan Regional Monitoring Program for Trace Substances
 
 
DECISION ID
97112
Region 2     
Guadalupe Slough
 
Pollutant: Silver
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 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. Zero of fifteen samples exceed the guideline.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of fifteen samples exceed the guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 97112, Silver
Region 2     
Guadalupe Slough
 
LOE ID: 91841
 
Pollutant: Silver
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 15
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed SFEI data for Guadalupe Slough to determine beneficial use support and results are as follows: 0 of 15 samples exceed the criterion for Silver.
Data Reference: Regional Monitoring Program data, Feb. 1993-Sep. 2008
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The dissolved silver criterion maximum concentration to protect aquatic life in saline water is 0.0019 mg/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Guadalupe Slough was collected at 1 monitoring site [ Sunnyvale - C-1-3]
Temporal Representation: Data was collected over the time period 2/1/1994-2/7/2001.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The 1999 Quality Assurance Project Plan Regional Monitoring Program for Trace Substances was used.
QAPP Information Reference(s): 1999 Quality Assurance Project Plan Regional Monitoring Program for Trace Substances
 
 
DECISION ID
97113
Region 2     
Guadalupe Slough
 
Pollutant: Zinc
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 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. Zero of eighteen samples exceed the guideline.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. Zero of eighteen samples exceed the guideline 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.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 97113, Zinc
Region 2     
Guadalupe Slough
 
LOE ID: 91842
 
Pollutant: Zinc
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 18
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: State Water Board staff assessed SFEI data for Guadalupe Slough to determine beneficial use support and results are as follows: 0 of 18 samples exceed the criterion for Zinc.
Data Reference: Regional Monitoring Program data, Feb. 1993-Sep. 2008
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The dissolved zinc criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in saline water is 0.081 mg/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for Guadalupe Slough was collected at 1 monitoring site [ Sunnyvale - C-1-3]
Temporal Representation: Data was collected over the time period 2/1/1994-2/7/2001.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The 1999 Quality Assurance Project Plan Regional Monitoring Program for Trace Substances was used.
QAPP Information Reference(s): 1999 Quality Assurance Project Plan Regional Monitoring Program for Trace Substances
 
 
DECISION ID
99544
Region 2     
Guadalupe Slough
 
Pollutant: Toxicity
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)(2016)
Revision Status Original
Sources: A Source Unknown
Expected TMDL Completion Date: 2029
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.6 of the Listing Policy. Under section 3.6 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. Two of sixteen samples exceed the guideline for water column toxicity.

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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Two of sixteen samples exceed the guideline and this exceeds 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.
 
Regional Board Decision 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.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 99544, Toxicity
Region 2     
Guadalupe Slough
 
LOE ID: 95813
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Sediment
Fraction: None
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 2
Number of Exceedances: 1
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: One of the 2 samples exhibited toxicity. A sample may have multiple toxicity test results but will be counted only once. A sample is defined as being collected on the same day at the same location with the same lab sample id (if provided).

The following test organisms and parameters were utilized for the toxicity tests: Eohaustorius estuarius (mean % survival), 1998; Mytilus galloprovincialis (mean % normal alive), 1998. The sample which exhibited toxicity was for Mytilus galloprovincialis collected August 1998.

Additional results were not included in the assessment due to control results of less than 90 percent for test parameter.
Data Reference: Regional Monitoring Program data, Feb. 1993-Sep. 2008
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant, animal, or aquatic life. Region 2 Basin Plan.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
 
Evaluation Guideline: Toxicity is defined as a significant reduction of test organism relative to the control (alpha < 0.01) and test organism survival is 80% or less than the control survival (at least 20% effect).
Guideline Reference: SWAMP_Memo_Toxicity_Data_Intrepretation
Guideline Reference: Methods for Assessing the Toxicity of Sediment-associated Contaminants with Estuarine and Marine Amphipods. June 1994. EPA 600/R-94/025
 
Spatial Representation: Samples were collected at site C-1-3.
Temporal Representation: The samples were collected August 1998.
Environmental Conditions:
QAPP Information: There is no QAPP available for data collected during this time period.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 99544, Toxicity
Region 2     
Guadalupe Slough
 
LOE ID: 95812
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Estuarine Habitat
 
Number of Samples: 16
Number of Exceedances: 2
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Two of the 16 samples exhibited toxicity. A sample may have multiple toxicity test results but will be counted only once. A sample is defined as being collected on the same day at the same location with the same lab sample id (if provided).

The following test organisms and parameters were utilized for the toxicity tests: Mytilus edulis (mean % normal development), 1996-97; and Americamysis bahia - formerly Mysidopsis bahia (mean % survival), 1994-2001. The two sample which exhibited toxicity were for Americamysis bahia collected January and July 1997.

Additional results were not included in the assessment due to control results of less than 90 percent for test parameter.
Data Reference: Regional Monitoring Program data, Feb. 1993-Sep. 2008
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant, animal, or aquatic life. Region 2 Basin Plan.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) - San Francisco Bay Region (Region 2)
 
Evaluation Guideline: Toxicity is defined as a significant reduction of test organism relative to the control (alpha < 0.05) and test organism survival is 80% or less than the control survival (at least 20% effect).
Guideline Reference: Method 1007.0: Mysid, Mysidopsis bahia, Survival, Growth, and Fecundity Test; Chronic Toxicity. Excerpt from: Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Marine and Estuarine Organisms. 3rd edition EPA-821-R-02-014
Guideline Reference: SWAMP_Memo_Toxicity_Data_Intrepretation
 
Spatial Representation: Samples were collected at site C-1-3.
Temporal Representation: The samples were collected twice each year (winter and summer) from 1994 - 2001.
Environmental Conditions:
QAPP Information: Data collected after 1999 follows the San Francisco Estuary Institute 1999 Quality Assurance Project Plan Regional Monitoring Program for Trace Substances.
QAPP Information Reference(s): 1999 Quality Assurance Project Plan Regional Monitoring Program for Trace Substances