Draft California 2024 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 2 - San Francisco Bay Region

Water Body Name: San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
Water Body ID: CAR2073202020210622039052
Water Body Type: River & Stream
 
DECISION ID
144184
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Alkalinity as CaCO3
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144184, Alkalinity as CaCO3
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 276986
 
Pollutant: Alkalinity as CaCO3
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00788 (San Ramon Creek 250m North of Paraiso Drive, San Ramon-207R00788).
Temporal Representation: The samples were collected between the dates of 2013-05-15 and 2013-05-15
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144184, Alkalinity as CaCO3
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 276988
 
Pollutant: Alkalinity as CaCO3
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: The samples were collected between the dates of 2013-04-29 and 2013-04-29
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144184, Alkalinity as CaCO3
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 276736
 
Pollutant: Alkalinity as CaCO3
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00379 (Green Valley Creek, West Branch).
Temporal Representation: The samples were collected between the dates of 2014-04-21 and 2014-04-21
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144184, Alkalinity as CaCO3
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 276989
 
Pollutant: Alkalinity as CaCO3
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00651 (Sans Crainte Creek).
Temporal Representation: The samples were collected between the dates of 2014-04-21 and 2014-04-21
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144184, Alkalinity as CaCO3
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 277008
 
Pollutant: Alkalinity as CaCO3
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3.
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00891 (Green Valley Creek).
Temporal Representation: The samples were collected between the dates of 2015-04-22 and 2015-04-22
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144184, Alkalinity as CaCO3
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 276987
 
Pollutant: Alkalinity as CaCO3
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00532 (Sycamore Creek 500m upstream from Sycamore Valley Road West near Messian Place, Danville-207R00532).
Temporal Representation: The samples were collected between the dates of 2013-04-29 and 2013-04-29
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144184, Alkalinity as CaCO3
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 276737
 
Pollutant: Alkalinity as CaCO3
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3.
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01163 (San Ramon Creek, 1.7 mi. SSE of Walnut Creek, South Main St.).
Temporal Representation: The samples were collected between the dates of 2015-05-04 and 2015-05-04
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144184, Alkalinity as CaCO3
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 276738
 
Pollutant: Alkalinity as CaCO3
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3.
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01227 (San Ramon Creek, 2.5 mi. SSE of Walnut Creek, Danville Blvd.).
Temporal Representation: The samples were collected between the dates of 2015-05-04 and 2015-05-04
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144184, Alkalinity as CaCO3
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 276754
 
Pollutant: Alkalinity as CaCO3
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP Perennial Stream Surveys data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3.
Data Reference: Field, Habitat, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207PS0150 (San Ramon Creek ~0.2mi above Livorna Rd.).
Temporal Representation: The samples were collected between the dates of 2012-06-13 and 2012-06-13
Environmental Conditions:
QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
 
DECISION ID
151011
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Ammonia
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
 
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.

32 lines of evidence are available in the administrative record to assess this pollutant. 1 of the 16 samples exceed the evaluation 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. 1 of 16 samples exceeded the evaluation 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:
 
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 279860
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01227 (San Ramon Creek, 2.5 mi. SSE of Walnut Creek, Danville Blvd.).
Temporal Representation: The samples were collected between the dates of 2015-05-04 and 2015-05-04
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 279924
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP Perennial Stream Surveys data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference: Field, Habitat, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207PS0150 (San Ramon Creek ~0.2mi above Livorna Rd.).
Temporal Representation: The samples were collected between the dates of 2012-06-13 and 2012-06-13
Environmental Conditions:
QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 279902
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01163 (San Ramon Creek, 1.7 mi. SSE of Walnut Creek, South Main St.).
Temporal Representation: The samples were collected between the dates of 2015-05-04 and 2015-05-04
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 277838
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2016 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01611 (San Ramon Creek).
Temporal Representation: The samples were collected between the dates of 2016-05-10 and 2016-05-10
Environmental Conditions:
QAPP Information: EOA, Inc.. 2016. Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 278468
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP Perennial Stream Surveys data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference: Field, Habitat, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207PS0150 (San Ramon Creek ~0.2mi above Livorna Rd.).
Temporal Representation: The samples were collected between the dates of 2012-06-13 and 2012-06-13
Environmental Conditions:
QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 277720
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01860 (Diablo Creek, off Blackhawk Rd, near Jacaranda Dr).
Temporal Representation: The samples were collected between the dates of 2017-05-16 and 2017-05-16
Environmental Conditions:
QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 278704
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00532 (Sycamore Creek 500m upstream from Sycamore Valley Road West near Messian Place, Danville-207R00532).
Temporal Representation: The samples were collected between the dates of 2013-04-29 and 2013-04-29
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 278221
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00651 (Sans Crainte Creek).
Temporal Representation: The samples were collected between the dates of 2014-04-21 and 2014-04-21
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 278222
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01227 (San Ramon Creek, 2.5 mi. SSE of Walnut Creek, Danville Blvd.).
Temporal Representation: The samples were collected between the dates of 2015-05-04 and 2015-05-04
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 278467
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2020 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R02075 (San Ramon Creek, 240m ENE of Danville Blvd and Vine Lane intersection).
Temporal Representation: The samples were collected between the dates of 2020-06-18 and 2020-06-18
Environmental Conditions:
QAPP Information: EOA, Inc.. 2000. Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project.
QAPP Information Reference(s): Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 278885
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01675 (Sans Crainte Creek, near the intersection of Rudgear Rd and Covington Ct).
Temporal Representation: The samples were collected between the dates of 2017-05-15 and 2017-05-15
Environmental Conditions:
QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 278711
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: The samples were collected between the dates of 2013-04-29 and 2013-04-29
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 278332
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2020 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R02884 (Sycamore Creek, 75m N of Barrenger Drive and Chadbourne Drive intersection curve).
Temporal Representation: The samples were collected between the dates of 2020-06-08 and 2020-06-08
Environmental Conditions:
QAPP Information: EOA, Inc.. 2000. Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project.
QAPP Information Reference(s): Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 278290
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00379 (Green Valley Creek, West Branch).
Temporal Representation: The samples were collected between the dates of 2014-04-21 and 2014-04-21
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 278314
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01931 (San Ramon Creek, off Glade Ln, near Arbor Ln).
Temporal Representation: The samples were collected between the dates of 2017-06-15 and 2017-06-15
Environmental Conditions:
QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 278977
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01812 (Sycamore Creek, near the intersection of Old Orchard Dr and Sycamore Valley Rd W).
Temporal Representation: The samples were collected between the dates of 2017-05-18 and 2017-05-18
Environmental Conditions:
QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 278293
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01163 (San Ramon Creek, 1.7 mi. SSE of Walnut Creek, South Main St.).
Temporal Representation: The samples were collected between the dates of 2015-05-04 and 2015-05-04
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 278707
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00788 (San Ramon Creek 250m North of Paraiso Drive, San Ramon-207R00788).
Temporal Representation: The samples were collected between the dates of 2013-05-15 and 2013-05-15
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 278315
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2020 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.
Objective/Criterion Reference: Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R03087 (Sycamore Creek, 40m S of Pepperwood Drive and Pepperwood Lane intersection).
Temporal Representation: The samples were collected between the dates of 2020-05-27 and 2020-05-27
Environmental Conditions:
QAPP Information: EOA, Inc.. 2000. Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project.
QAPP Information Reference(s): Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 279600
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00651 (Sans Crainte Creek).
Temporal Representation: The samples were collected between the dates of 2014-04-21 and 2014-04-21
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 279356
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01931 (San Ramon Creek, off Glade Ln, near Arbor Ln).
Temporal Representation: The samples were collected between the dates of 2017-06-15 and 2017-06-15
Environmental Conditions:
QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 279435
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00788 (San Ramon Creek 250m North of Paraiso Drive, San Ramon-207R00788).
Temporal Representation: The samples were collected between the dates of 2013-05-15 and 2013-05-15
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 279358
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2020 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R02075 (San Ramon Creek, 240m ENE of Danville Blvd and Vine Lane intersection).
Temporal Representation: The samples were collected between the dates of 2020-06-18 and 2020-06-18
Environmental Conditions:
QAPP Information: EOA, Inc.. 2000. Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project.
QAPP Information Reference(s): Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 279253
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2020 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R02884 (Sycamore Creek, 75m N of Barrenger Drive and Chadbourne Drive intersection curve).
Temporal Representation: The samples were collected between the dates of 2020-06-08 and 2020-06-08
Environmental Conditions:
QAPP Information: EOA, Inc.. 2000. Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project.
QAPP Information Reference(s): Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 279436
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: The samples were collected between the dates of 2013-04-29 and 2013-04-29
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 279859
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00379 (Green Valley Creek, West Branch).
Temporal Representation: The samples were collected between the dates of 2014-04-21 and 2014-04-21
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 279737
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2020 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R03087 (Sycamore Creek, 40m S of Pepperwood Drive and Pepperwood Lane intersection).
Temporal Representation: The samples were collected between the dates of 2020-05-27 and 2020-05-27
Environmental Conditions:
QAPP Information: EOA, Inc.. 2000. Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project.
QAPP Information Reference(s): Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 279799
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01812 (Sycamore Creek, near the intersection of Old Orchard Dr and Sycamore Valley Rd W).
Temporal Representation: The samples were collected between the dates of 2017-05-18 and 2017-05-18
Environmental Conditions:
QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 279798
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01675 (Sans Crainte Creek, near the intersection of Rudgear Rd and Covington Ct).
Temporal Representation: The samples were collected between the dates of 2017-05-15 and 2017-05-15
Environmental Conditions:
QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 279861
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2016 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01611 (San Ramon Creek).
Temporal Representation: The samples were collected between the dates of 2016-05-10 and 2016-05-10
Environmental Conditions:
QAPP Information: EOA, Inc.. 2016. Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 279355
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01860 (Diablo Creek, off Blackhawk Rd, near Jacaranda Dr).
Temporal Representation: The samples were collected between the dates of 2017-05-16 and 2017-05-16
Environmental Conditions:
QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 151011, Ammonia
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 279434
 
Pollutant: Ammonia (Unionized)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N, Unionized.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.20 Un-Ionized Ammonia: The discharge of wastes shall not cause receiving waters to contain concentrations of un-ionized ammonia in excess 0.025 mg/l (as N), expressed as an annual median.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00532 (Sycamore Creek 500m upstream from Sycamore Valley Road West near Messian Place, Danville-207R00532).
Temporal Representation: The samples were collected between the dates of 2013-04-29 and 2013-04-29
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144157
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Anthracene
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144157, Anthracene
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 269653
 
Pollutant: Anthracene
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Anthracene .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for anthracene is the probable effect concentration (PEC) of 845 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144157, Anthracene
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 269649
 
Pollutant: Anthracene
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Anthracene .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for anthracene is the probable effect concentration (PEC) of 845 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144158
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Arsenic
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144158, Arsenic
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 269556
 
Pollutant: Arsenic
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Arsenic .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for arsenic is the probable effect concentration (PEC) of 33 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144158, Arsenic
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 269821
 
Pollutant: Arsenic
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Arsenic .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for arsenic is the probable effect concentration (PEC) of 33 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
154236
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Benthic Community Effects
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
 
Regional Board Conclusion: Benthic community effects are being considered for placement on the CWA section 303(d) List under section 3.9 of the Listing Policy. Under section 3.9, when data show benthic community degradation and there is at least one pollutant impairment that could impact benthic macroinvertebrates, the waterbody is placed on the 303(d) List for benthic community effects.

Sixteen lines of evidence evaluating benthic macroinvertebrate bioassessment data are available in the administrative record to assess this indicator. Sixteen of sixteen benthic-macroinvertebrate samples exceed the California Stream Condition Index (CSCI) impairment threshold of 0.79. At least one line of evidence includes sufficient pollutant exceedances to indicate the waterbody is impaired for at least one pollutant. However, there is insufficient data and/or information to determine if at least one pollutant could be impacting benthic macroinvertebrates.

Based on the readily available data and information, the evidence indicates that there is sufficient justification against placing Benthic Community Effects in this waterbody segment on the CWA section 303(d) List. Although there is insufficient data and/or information to make a beneficial use support determination, the exceedances of the benthic macroinvertebrate samples indicate beneficial uses may be potentially threatened.

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. Sixteen of sixteen benthic macroinvertebrate bioassessment samples had CSCI scores below 0.79.
4. At least one line of evidence includes sufficient pollutant exceedances to indicate the waterbody is impaired for at least one pollutant related to aquatic life; however, data and/or information are insufficient to determine if the pollutant(s) is impacting benthic macroinvertebrates.
5. 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:
 
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 306274
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Water Board staff assessed data for 207R01812 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.403 to 0.403.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use. 
Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings
 
Spatial Representation: Samples were collected from station 207R01812.
Temporal Representation: Samples were collected from 5/18/2017 to 5/18/2017.
Environmental Conditions:
QAPP Information: Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 306275
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Water Board staff assessed data for 207R01931 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.626 to 0.626.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use. 
Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings
 
Spatial Representation: Samples were collected from station 207R01931.
Temporal Representation: Samples were collected from 6/15/2017 to 6/15/2017.
Environmental Conditions:
QAPP Information: Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 306317
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Water Board staff assessed data for 207R01675 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.399 to 0.399.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use. 
Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings
 
Spatial Representation: Samples were collected from station 207R01675.
Temporal Representation: Samples were collected from 5/15/2017 to 5/15/2017.
Environmental Conditions:
QAPP Information: Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 306311
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Water Board staff assessed data for 207R00379 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.379397 to 0.379397.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use. 
Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings
 
Spatial Representation: Samples were collected from station 207R00379.
Temporal Representation: Samples were collected from 4/21/2014 to 4/21/2014.
Environmental Conditions:
QAPP Information: Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 306310
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Water Board staff assessed data for 207R00788 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.571666 to 0.571666.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use. 
Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings
 
Spatial Representation: Samples were collected from station 207R00788.
Temporal Representation: Samples were collected from 5/15/2013 to 5/15/2013.
Environmental Conditions:
QAPP Information: Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 306306
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Water Board staff assessed data for 207CE0230 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.617122352 to 0.617122352.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use. 
Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings
 
Spatial Representation: Samples were collected from station 207CE0230.
Temporal Representation: Samples were collected from 5/24/2006 to 5/24/2006.
Environmental Conditions:
QAPP Information: Data were collected using Surface Water Ambient Monitoring Program protocols
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 270219
 
Pollutant: Bifenthrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Bifenthrin .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for bifenthrin is the median lethal concentration (LC50) of 0.43 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.43 ug/g is the geometric mean of LC50 values for bifenthrin (Amweg et al., 2005 and Amweg and Weston, 2007).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Guideline Reference: Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 270163
 
Pollutant: Bifenthrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Bifenthrin .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for bifenthrin is the median lethal concentration (LC50) of 0.43 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.43 ug/g is the geometric mean of LC50 values for bifenthrin (Amweg et al., 2005 and Amweg and Weston, 2007).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Guideline Reference: Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 276098
 
Pollutant: Pyrethroids
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Pyrethroids .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for the protection of aquatic life from pyrethroids is one toxic unit. Individual pyrethroid concentrations in sediment were normalized to organic carbon content, divided by the respective LC50 and then summed. A sum over over one toxic unit is an exceedance of the evaluation guideline (Amweg et al. 2006).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Guideline Reference: Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15
Guideline Reference: Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.
Guideline Reference: Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.
Guideline Reference: Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids
Guideline Reference: Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 276044
 
Pollutant: Pyrethroids
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Pyrethroids .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for the protection of aquatic life from pyrethroids is one toxic unit. Individual pyrethroid concentrations in sediment were normalized to organic carbon content, divided by the respective LC50 and then summed. A sum over over one toxic unit is an exceedance of the evaluation guideline (Amweg et al. 2006).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
Guideline Reference: Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15
Guideline Reference: Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.
Guideline Reference: Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.
Guideline Reference: Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids
Guideline Reference: Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 268688
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 3
Number of Exceedances: 2
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: 2 of the 3 samples collected by BASMAA RMC Monitoring in WY2015 for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Ceriodaphnia dubia for Survival, Pimephales promelas for Biomass (wt/orig indiv), Hyalella azteca for Survival, Selenastrum capricornutum for Total Cell Count, Ceriodaphnia dubia for Young/female, Pimephales promelas for Survival. The following tests exhibited toxicity: Hyalella azteca for Survival on 2015-02-06, Hyalella azteca for Survival on 2015-04-07.
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference: Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
 
Spatial Representation: The samples were collected at monitoring site: 207R00891 ( Green Valley Creek ).
Temporal Representation: The samples were collected between the dates of 2015-02-06 and 2015-07-07.
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 268569
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Sediment
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: 1 of the 1 samples collected by BASMAA RMC Monitoring in WY2015 for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Growth (wt/surv indiv), Hyalella azteca for Survival. The following tests exhibited toxicity: Hyalella azteca for Growth (wt/surv indiv) on 2015-07-07.
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference: Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
 
Spatial Representation: The samples were collected at monitoring site: 207R00891 ( Green Valley Creek ).
Temporal Representation: The samples were collected between the dates of 2015-07-07 and 2015-07-07.
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 268598
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 1
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: 1 of the 2 samples collected by BASMAA RMC Monitoring in WY2013 for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Ceriodaphnia dubia for Survival, Pimephales promelas for Biomass (wt/orig indiv), Selenastrum capricornutum for Total Cell Count, Ceriodaphnia dubia for Young/female, Pimephales promelas for Survival, Hyalella azteca for Survival. The following tests exhibited toxicity: Pimephales promelas for Biomass (wt/orig indiv) on 2013-07-09, Hyalella azteca for Survival on 2013-07-09, Pimephales promelas for Survival on 2013-07-09.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference: Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
 
Spatial Representation: The samples were collected at monitoring site: 207R00271 ( Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271 ).
Temporal Representation: The samples were collected between the dates of 2013-03-06 and 2013-07-09.
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 268605
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Sediment
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: 1 of the 1 samples collected by BASMAA RMC Monitoring in WY2013 for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Growth (wt/surv indiv), Hyalella azteca for Survival. The following tests exhibited toxicity: Hyalella azteca for Growth (wt/surv indiv) on 2013-07-09, Hyalella azteca for Survival on 2013-07-09.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms. Detrimental responses include, but are not limited to, decreased growth rate and decreased reproductive success of resident or indicator species. There shall be no acute toxicity in ambient waters. Acute toxicity is defined as a median of less than 90 percent survival, or less than 70 percent survival, 10 percent of the time, of test organisms in a 96-hour static or continuous flow test. There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. Attainment of this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, or toxicity tests (including those described in Chapter 4), or other methods selected by the Water Board. The Water Board will also consider other relevant information and numeric criteria and guidelines for toxic substances developed by other agencies as appropriate.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing.  An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold.  The default evaluation threshold is 20% unless otherwise stated.
Guideline Reference: Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013
 
Spatial Representation: The samples were collected at monitoring site: 207R00271 ( Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271 ).
Temporal Representation: The samples were collected between the dates of 2013-07-09 and 2013-07-09.
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 306315
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Water Board staff assessed data for 207R01227 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.496947 to 0.496947.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use. 
Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings
 
Spatial Representation: Samples were collected from station 207R01227.
Temporal Representation: Samples were collected from 5/4/2015 to 5/4/2015.
Environmental Conditions:
QAPP Information: Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 306312
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Water Board staff assessed data for 207R00651 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.316451 to 0.316451.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use. 
Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings
 
Spatial Representation: Samples were collected from station 207R00651.
Temporal Representation: Samples were collected from 4/21/2014 to 4/21/2014.
Environmental Conditions:
QAPP Information: Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 306318
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Water Board staff assessed data for 207R01860 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.4285926 to 0.4285926.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use. 
Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings
 
Spatial Representation: Samples were collected from station 207R01860.
Temporal Representation: Samples were collected from 5/16/2017 to 5/16/2017.
Environmental Conditions:
QAPP Information: Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 306308
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Water Board staff assessed data for 207R00271 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.3256 to 0.3256.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use. 
Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings
 
Spatial Representation: Samples were collected from station 207R00271.
Temporal Representation: Samples were collected from 4/29/2013 to 4/29/2013.
Environmental Conditions:
QAPP Information: Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 306313
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Water Board staff assessed data for 207R00891 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.357506 to 0.357506.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use. 
Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings
 
Spatial Representation: Samples were collected from station 207R00891.
Temporal Representation: Samples were collected from 4/22/2015 to 4/22/2015.
Environmental Conditions:
QAPP Information: Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 306316
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Water Board staff assessed data for 207R01611 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.600474 to 0.600474.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use. 
Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings
 
Spatial Representation: Samples were collected from station 207R01611.
Temporal Representation: Samples were collected from 5/10/2016 to 5/10/2016.
Environmental Conditions:
QAPP Information: Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 306309
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Water Board staff assessed data for 207R00532 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.388261 to 0.388261.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use. 
Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings
 
Spatial Representation: Samples were collected from station 207R00532.
Temporal Representation: Samples were collected from 4/29/2013 to 4/29/2013.
Environmental Conditions:
QAPP Information: Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 306307
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Water Board staff assessed data for 207PS0150 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.567103605 to 0.567103605.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use. 
Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings
 
Spatial Representation: Samples were collected from station 207PS0150.
Temporal Representation: Samples were collected from 6/13/2012 to 6/13/2012.
Environmental Conditions:
QAPP Information: Data were collected using Surface Water Ambient Monitoring Program protocols
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 306305
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Water Board staff assessed data for 207CE0058 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.500246291 to 0.500246291.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use. 
Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings
 
Spatial Representation: Samples were collected from station 207CE0058.
Temporal Representation: Samples were collected from 5/19/2004 to 5/19/2004.
Environmental Conditions:
QAPP Information: Data were collected using Surface Water Ambient Monitoring Program protocols
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 154236, Benthic Community Effects
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 306314
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: Water Board staff assessed data for 207R01163 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.620409 to 0.620409.
Data Reference: California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use. 
Guideline Reference: Bioassessment in complex environments: designing an index for consistent meaning in different settings
 
Spatial Representation: Samples were collected from station 207R01163.
Temporal Representation: Samples were collected from 5/4/2015 to 5/4/2015.
Environmental Conditions:
QAPP Information: Data were collected according to BASMAA Regional Monitoring Coalition sampling protocols.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144160
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Benzo(a)anthracene
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144160, Benzo(a)anthracene
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 270032
 
Pollutant: Benzo(a)anthracene
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Benz(a)anthracene .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for benz[a]anthrazene is the probable effect concentration (PEC) of 1050 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144160, Benzo(a)anthracene
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 269927
 
Pollutant: Benzo(a)anthracene
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Benz(a)anthracene .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for benz[a]anthrazene is the probable effect concentration (PEC) of 1050 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144159
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Benzo(a)pyrene
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144159, Benzo(a)pyrene
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 270232
 
Pollutant: Benzo(a)pyrene
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Benzo(a)pyrene .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for benzo[a]pyrene is the probable effect concentration (PEC) of 1450 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144159, Benzo(a)pyrene
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 270331
 
Pollutant: Benzo(a)pyrene
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Benzo(a)pyrene .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for benzo[a]pyrene is the probable effect concentration (PEC) of 1450 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144161
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Cadmium
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144161, Cadmium
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 270503
 
Pollutant: Cadmium
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cadmium .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for cadmium is the probable effect concentration (PEC) of 4.98 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144161, Cadmium
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 270756
 
Pollutant: Cadmium
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cadmium .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for cadmium is the probable effect concentration (PEC) of 4.98 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144162
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Chlordane
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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 the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 144162, Chlordane
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 270924
 
Pollutant: Chlordane
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chlordane .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for chlordane is the probable effect concentration (PEC) of 17.6 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144163
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Chloride
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144163, Chloride
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 280991
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP Perennial Stream Surveys data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Habitat, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207PS0150 (San Ramon Creek ~0.2mi above Livorna Rd.).
Temporal Representation: The samples were collected between the dates of 2012-06-13 and 2012-06-13
Environmental Conditions:
QAPP Information: SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..
QAPP Information Reference(s): This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.
 
Line of Evidence (LOE) for Decision ID 144163, Chloride
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 280670
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00891 (Green Valley Creek).
Temporal Representation: The samples were collected between the dates of 2015-04-22 and 2015-04-22
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144163, Chloride
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 281467
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: The samples were collected between the dates of 2013-04-29 and 2013-04-29
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144163, Chloride
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 280835
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01675 (Sans Crainte Creek, near the intersection of Rudgear Rd and Covington Ct).
Temporal Representation: The samples were collected between the dates of 2017-05-15 and 2017-05-15
Environmental Conditions:
QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144163, Chloride
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 281814
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2020 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R02884 (Sycamore Creek, 75m N of Barrenger Drive and Chadbourne Drive intersection curve).
Temporal Representation: The samples were collected between the dates of 2020-06-08 and 2020-06-08
Environmental Conditions:
QAPP Information: EOA, Inc.. 2000. Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project.
QAPP Information Reference(s): Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project
 
Line of Evidence (LOE) for Decision ID 144163, Chloride
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 281731
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2020 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R03087 (Sycamore Creek, 40m S of Pepperwood Drive and Pepperwood Lane intersection).
Temporal Representation: The samples were collected between the dates of 2020-05-27 and 2020-05-27
Environmental Conditions:
QAPP Information: EOA, Inc.. 2000. Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project.
QAPP Information Reference(s): Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project
 
Line of Evidence (LOE) for Decision ID 144163, Chloride
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 281124
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00532 (Sycamore Creek 500m upstream from Sycamore Valley Road West near Messian Place, Danville-207R00532).
Temporal Representation: The samples were collected between the dates of 2013-04-29 and 2013-04-29
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144163, Chloride
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 281340
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00379 (Green Valley Creek, West Branch).
Temporal Representation: The samples were collected between the dates of 2014-04-21 and 2014-04-21
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144163, Chloride
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 280659
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01860 (Diablo Creek, off Blackhawk Rd, near Jacaranda Dr).
Temporal Representation: The samples were collected between the dates of 2017-05-16 and 2017-05-16
Environmental Conditions:
QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144163, Chloride
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 281497
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00788 (San Ramon Creek 250m North of Paraiso Drive, San Ramon-207R00788).
Temporal Representation: The samples were collected between the dates of 2013-05-15 and 2013-05-15
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144163, Chloride
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 280980
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01163 (San Ramon Creek, 1.7 mi. SSE of Walnut Creek, South Main St.).
Temporal Representation: The samples were collected between the dates of 2015-05-04 and 2015-05-04
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144163, Chloride
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 281359
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01931 (San Ramon Creek, off Glade Ln, near Arbor Ln).
Temporal Representation: The samples were collected between the dates of 2017-06-15 and 2017-06-15
Environmental Conditions:
QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144163, Chloride
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 280660
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01812 (Sycamore Creek, near the intersection of Old Orchard Dr and Sycamore Valley Rd W).
Temporal Representation: The samples were collected between the dates of 2017-05-18 and 2017-05-18
Environmental Conditions:
QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144163, Chloride
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 281973
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2020 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R02075 (San Ramon Creek, 240m ENE of Danville Blvd and Vine Lane intersection).
Temporal Representation: The samples were collected between the dates of 2020-06-18 and 2020-06-18
Environmental Conditions:
QAPP Information: EOA, Inc.. 2000. Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project.
QAPP Information Reference(s): Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project
 
Line of Evidence (LOE) for Decision ID 144163, Chloride
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 281128
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01227 (San Ramon Creek, 2.5 mi. SSE of Walnut Creek, Danville Blvd.).
Temporal Representation: The samples were collected between the dates of 2015-05-04 and 2015-05-04
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144163, Chloride
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 281525
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00651 (Sans Crainte Creek).
Temporal Representation: The samples were collected between the dates of 2014-04-21 and 2014-04-21
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144163, Chloride
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 280805
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2016 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01611 (San Ramon Creek).
Temporal Representation: The samples were collected between the dates of 2016-05-10 and 2016-05-10
Environmental Conditions:
QAPP Information: EOA, Inc.. 2016. Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144164
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Chlorine
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
 
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 the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 144164, Chlorine
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 282493
 
Pollutant: Chlorine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2020 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R02884 (Sycamore Creek, 75m N of Barrenger Drive and Chadbourne Drive intersection curve).
Temporal Representation: The samples were collected between the dates of 2020-06-08 and 2020-06-08
Environmental Conditions:
QAPP Information: EOA, Inc.. 2000. Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project.
QAPP Information Reference(s): Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project
 
Line of Evidence (LOE) for Decision ID 144164, Chlorine
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 282743
 
Pollutant: Chlorine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01812 (Sycamore Creek, near the intersection of Old Orchard Dr and Sycamore Valley Rd W).
Temporal Representation: The samples were collected between the dates of 2017-05-18 and 2017-05-18
Environmental Conditions:
QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144164, Chlorine
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 282628
 
Pollutant: Chlorine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Chlorine, Total Residual.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: The samples were collected between the dates of 2013-04-29 and 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144164, Chlorine
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 282661
 
Pollutant: Chlorine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00379 (Green Valley Creek, West Branch).
Temporal Representation: The samples were collected between the dates of 2014-04-21 and 2014-04-21
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144164, Chlorine
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 282742
 
Pollutant: Chlorine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2016 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01611 (San Ramon Creek).
Temporal Representation: The samples were collected between the dates of 2016-05-10 and 2016-05-10
Environmental Conditions:
QAPP Information: EOA, Inc.. 2016. Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144164, Chlorine
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 282617
 
Pollutant: Chlorine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2020 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R02075 (San Ramon Creek, 240m ENE of Danville Blvd and Vine Lane intersection).
Temporal Representation: The samples were collected between the dates of 2020-06-18 and 2020-06-18
Environmental Conditions:
QAPP Information: EOA, Inc.. 2000. Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project.
QAPP Information Reference(s): Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project
 
Line of Evidence (LOE) for Decision ID 144164, Chlorine
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 282234
 
Pollutant: Chlorine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00532 (Sycamore Creek 500m upstream from Sycamore Valley Road West near Messian Place, Danville-207R00532).
Temporal Representation: The samples were collected between the dates of 2013-04-29 and 2013-04-29
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144164, Chlorine
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 282665
 
Pollutant: Chlorine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01860 (Diablo Creek, off Blackhawk Rd, near Jacaranda Dr).
Temporal Representation: The samples were collected between the dates of 2017-05-16 and 2017-05-16
Environmental Conditions:
QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144164, Chlorine
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 282832
 
Pollutant: Chlorine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01675 (Sans Crainte Creek, near the intersection of Rudgear Rd and Covington Ct).
Temporal Representation: The samples were collected between the dates of 2017-05-15 and 2017-05-15
Environmental Conditions:
QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144164, Chlorine
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 282651
 
Pollutant: Chlorine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R01931 (San Ramon Creek, off Glade Ln, near Arbor Ln).
Temporal Representation: The samples were collected between the dates of 2017-06-15 and 2017-06-15
Environmental Conditions:
QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144164, Chlorine
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 282745
 
Pollutant: Chlorine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00651 (Sans Crainte Creek).
Temporal Representation: The samples were collected between the dates of 2014-04-21 and 2014-04-21
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144164, Chlorine
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 282684
 
Pollutant: Chlorine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00788 (San Ramon Creek 250m North of Paraiso Drive, San Ramon-207R00788).
Temporal Representation: The samples were collected between the dates of 2013-05-15 and 2013-05-15
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144164, Chlorine
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 282727
 
Pollutant: Chlorine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2020 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorine, Total Residual.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan for the San Francisco Bay Basin: Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average).
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R03087 (Sycamore Creek, 40m S of Pepperwood Drive and Pepperwood Lane intersection).
Temporal Representation: The samples were collected between the dates of 2020-05-27 and 2020-05-27
Environmental Conditions:
QAPP Information: EOA, Inc.. 2000. Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project.
QAPP Information Reference(s): Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project
 
 
DECISION ID
144188
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Chromium
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144188, Chromium
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 271306
 
Pollutant: Chromium
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chromium .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for chromium is the probable effect concentration (PEC) of 111 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144188, Chromium
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 270896
 
Pollutant: Chromium
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chromium .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for chromium is the probable effect concentration (PEC) of 111 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144165
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Chrysene (C1-C4)
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144165, Chrysene (C1-C4)
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 271257
 
Pollutant: Chrysene (C1-C4)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chrysene .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for chrysene is the probable effect concentration (PEC) of 1290 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144165, Chrysene (C1-C4)
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 271176
 
Pollutant: Chrysene (C1-C4)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Chrysene .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for chrysene is the probable effect concentration (PEC) of 1290 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144166
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Copper
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144166, Copper
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 271531
 
Pollutant: Copper
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Copper .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for copper is the probable effect concentration (PEC) of 149 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144166, Copper
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 271536
 
Pollutant: Copper
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Copper .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for copper is the probable effect concentration (PEC) of 149 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144185
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Cyfluthrin
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144185, Cyfluthrin
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 271746
 
Pollutant: Cyfluthrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cyfluthrin, total .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for cyfluthrin is the median lethal concentration (LC50) of 1.1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.1 ug/g is the geometric mean of LC50 values for cyfluthrin (Amweg et al., 2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144185, Cyfluthrin
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 271982
 
Pollutant: Cyfluthrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cyfluthrin, total .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for cyfluthrin is the median lethal concentration (LC50) of 1.1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.1 ug/g is the geometric mean of LC50 values for cyfluthrin (Amweg et al., 2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144187
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Cyhalothrin, Lambda
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144187, Cyhalothrin, Lambda
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 271913
 
Pollutant: Cyhalothrin, Lambda
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cyhalothrin, Total lambda- .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for lambda-cyhalothrin is the median lethal concentration (LC50) of 0.44 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.44 ug/g is the geometric mean of LC50 values for lambda-cyhalothrin (Amweg et al., 2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144187, Cyhalothrin, Lambda
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 271790
 
Pollutant: Cyhalothrin, Lambda
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cyhalothrin, Total lambda- .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for lambda-cyhalothrin is the median lethal concentration (LC50) of 0.44 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.44 ug/g is the geometric mean of LC50 values for lambda-cyhalothrin (Amweg et al., 2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144183
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Cypermethrin
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144183, Cypermethrin
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 272034
 
Pollutant: Cypermethrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cypermethrin, Total .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for cypermethrin is the median lethal concentration (LC50) of 0.3 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.3 ug/g is the geometric mean of LC50 values for cypermethrin from Maund et al., (2002).
Guideline Reference: Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144183, Cypermethrin
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 272214
 
Pollutant: Cypermethrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Cypermethrin, Total .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for cypermethrin is the median lethal concentration (LC50) of 0.3 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.3 ug/g is the geometric mean of LC50 values for cypermethrin from Maund et al., (2002).
Guideline Reference: Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
148140
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: DDD (Dichlorodiphenyldichloroethane)
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 148140, DDD (Dichlorodiphenyldichloroethane)
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 272060
 
Pollutant: DDD (Dichlorodiphenyldichloroethane)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDD (Dichlorodiphenyldichloroethane) .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for the sum of DDD is the probable effect concentration (PEC) of 28 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 148140, DDD (Dichlorodiphenyldichloroethane)
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 272057
 
Pollutant: DDD (Dichlorodiphenyldichloroethane)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDD (Dichlorodiphenyldichloroethane) .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for the sum of DDD is the probable effect concentration (PEC) of 28 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
148196
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: DDE (Dichlorodiphenyldichloroethylene)
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 148196, DDE (Dichlorodiphenyldichloroethylene)
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 272282
 
Pollutant: DDE (Dichlorodiphenyldichloroethylene)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDE (Dichlorodiphenyldichloroethylene) .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for the sum of DDE is the probable effect concentration (PEC) of 31.3 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 148196, DDE (Dichlorodiphenyldichloroethylene)
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 272028
 
Pollutant: DDE (Dichlorodiphenyldichloroethylene)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDE (Dichlorodiphenyldichloroethylene) .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for the sum of DDE is the probable effect concentration (PEC) of 31.3 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
148344
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: DDT (Dichlorodiphenyltrichloroethane)
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
 
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 the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 148344, DDT (Dichlorodiphenyltrichloroethane)
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 272525
 
Pollutant: DDT (Dichlorodiphenyltrichloroethane)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDT (Dichlorodiphenyltrichloroethane) .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for the sum of DDT is the probable effect concentration (PEC) of 62.9 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 148344, DDT (Dichlorodiphenyltrichloroethane)
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 276319
 
Pollutant: Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD) .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for total DDTs is the probable effect concentration (PEC) of 572 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 148344, DDT (Dichlorodiphenyltrichloroethane)
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 275855
 
Pollutant: Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD) .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for total DDTs is the probable effect concentration (PEC) of 572 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 148344, DDT (Dichlorodiphenyltrichloroethane)
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 272068
 
Pollutant: DDT (Dichlorodiphenyltrichloroethane)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDT (Dichlorodiphenyltrichloroethane) .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for the sum of DDT is the probable effect concentration (PEC) of 62.9 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144186
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Deltamethrin
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144186, Deltamethrin
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 272513
 
Pollutant: Deltamethrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Deltamethrin .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for deltamethrin is the median lethal concentration (LC50) of 0.79 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.79 ug/g is the geometric mean of LC50 values for deltamethrin (Amweg et al., 2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144186, Deltamethrin
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 272491
 
Pollutant: Deltamethrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for Deltamethrin .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for deltamethrin is the median lethal concentration (LC50) of 0.79 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.79 ug/g is the geometric mean of LC50 values for deltamethrin (Amweg et al., 2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144167
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Dieldrin
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144167, Dieldrin
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 272765
 
Pollutant: Dieldrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Dieldrin .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for dieldrin is the probable effect concentration (PEC) of 61.8 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144167, Dieldrin
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 272784
 
Pollutant: Dieldrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Dieldrin .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for dieldrin is the probable effect concentration (PEC) of 61.8 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144168
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Endrin
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144168, Endrin
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 272715
 
Pollutant: Endrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Endrin .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for endrin is the probable effect concentration (PEC) of 207 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144168, Endrin
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 272882
 
Pollutant: Endrin
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Endrin .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for endrin is the probable effect concentration (PEC) of 207 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144189
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Esfenvalerate/Fenvalerate
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144189, Esfenvalerate/Fenvalerate
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 273090
 
Pollutant: Esfenvalerate/Fenvalerate
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Esfenvalerate/Fenvalerate, Total .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.5 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.5 ug/g is the geometric mean of LC50 values for esfenvalerate/fenvalerate (Amweg et al., 2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144189, Esfenvalerate/Fenvalerate
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 273091
 
Pollutant: Esfenvalerate/Fenvalerate
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Esfenvalerate/Fenvalerate, Total .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.5 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.5 ug/g is the geometric mean of LC50 values for esfenvalerate/fenvalerate (Amweg et al., 2005).
Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144169
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Fluoranthene
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144169, Fluoranthene
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 273356
 
Pollutant: Fluoranthene
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fluoranthene .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for fluoranthene is the probable effect concentration (PEC) of 2230 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144169, Fluoranthene
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 273414
 
Pollutant: Fluoranthene
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fluoranthene .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for fluoranthene is the probable effect concentration (PEC) of 2230 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144170
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Fluorene
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144170, Fluorene
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 273387
 
Pollutant: Fluorene
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fluorene .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for fluorene is the probable effect concentration (PEC) for Fluorene is 536 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144170, Fluorene
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 273651
 
Pollutant: Fluorene
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fluorene .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for fluorene is the probable effect concentration (PEC) for Fluorene is 536 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
148714
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Indicator Bacteria
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
 
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 the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 148714, Indicator Bacteria
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 299860
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: STV
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective to protect the REC-1 beneficial use where the salinity is less than 1 parts per thousand 95 percent or more of the time applies a statistical threshold value to E. coli of 320 cfu/100 mL, not to be exceeded by more than 10 percent of samples within a calendar month (ISWEBE 2018).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): 207R01163 (San Ramon Creek, 1.7 mi. SSE of Walnut Creek, South Main St.).
Temporal Representation: The samples were collected between the days of 2015-06-30 and 2015-06-30 .
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 148714, Indicator Bacteria
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 299741
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: STV
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2020 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective to protect the REC-1 beneficial use where the salinity is less than 1 parts per thousand 95 percent or more of the time applies a statistical threshold value to E. coli of 320 cfu/100 mL, not to be exceeded by more than 10 percent of samples within a calendar month (ISWEBE 2018).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): 207R01163 (San Ramon Creek, 1.7 mi. SSE of Walnut Creek, South Main St.).
Temporal Representation: The samples were collected between the days of 2020-08-05 and 2020-08-05 .
Environmental Conditions:
QAPP Information: EOA, Inc.. 2000. Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project.
QAPP Information Reference(s): Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project
 
Line of Evidence (LOE) for Decision ID 148714, Indicator Bacteria
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 299647
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: 90th percentile
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the water quality threshold for Coliform, Fecal. The water quality threshold is based on a 30-day 90% percentile.
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.1 Bacteria: Table 3-1 provides a summary of the bacterial water quality objectives and identifies the sources of those objectives. The fecal coliform objective for non-contact recreation is a 30-day 90th percentile less than 4000 MPN/100 ML.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): 207R01163 (San Ramon Creek, 1.7 mi. SSE of Walnut Creek, South Main St.).
Temporal Representation: The samples were collected between the days of 2015-06-30 and 2015-06-30 .
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 148714, Indicator Bacteria
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 299843
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: STV
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 2
Number of Exceedances: 2
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 2 of the 2 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective to protect the REC-1 beneficial use where the salinity is less than 1 parts per thousand 95 percent or more of the time applies a statistical threshold value to E. coli of 320 cfu/100 mL, not to be exceeded by more than 10 percent of samples within a calendar month (ISWEBE 2018).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): 207R01675 (Sans Crainte Creek, near the intersection of Rudgear Rd and Covington Ct).
Temporal Representation: The samples were collected between the days of 2017-07-24 and 2018-06-28 .
Environmental Conditions:
QAPP Information: EOA, Inc., Applied Marine Sciences, Armand Ruby Consulting . 2016. BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan.
QAPP Information Reference(s): BASMAA Regional Monitoring Coalition Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 148714, Indicator Bacteria
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 299603
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: 90th percentile
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the water quality threshold for Coliform, Fecal. The water quality threshold is based on a 30-day 90% percentile.
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives, Section 3.3.1 Bacteria: Table 3-1 provides a summary of the bacterial water quality objectives and identifies the sources of those objectives. The fecal coliform objective for non-contact recreation is a 30-day 90th percentile less than 4000 MPN/100 ML.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): 207R00891 (Green Valley Creek).
Temporal Representation: The samples were collected between the days of 2015-06-30 and 2015-06-30 .
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 148714, Indicator Bacteria
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 299602
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: STV
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective to protect the REC-1 beneficial use where the salinity is less than 1 parts per thousand 95 percent or more of the time applies a statistical threshold value to E. coli of 320 cfu/100 mL, not to be exceeded by more than 10 percent of samples within a calendar month (ISWEBE 2018).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): 207R00891 (Green Valley Creek).
Temporal Representation: The samples were collected between the days of 2015-06-30 and 2015-06-30 .
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144171
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Lead
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144171, Lead
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 273987
 
Pollutant: Lead
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Lead .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for lead is the probable effect concentration (PEC) of 128 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144171, Lead
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 274080
 
Pollutant: Lead
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Lead .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for lead is the probable effect concentration (PEC) of 128 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144172
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144172, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 273723
 
Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for HCH, gamma- .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for lindane is the probable effect concentration (PEC) for Lindane is 4.99 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144172, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 273719
 
Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for HCH, gamma- .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for lindane is the probable effect concentration (PEC) for Lindane is 4.99 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
145505
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Mercury
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 145505, Mercury
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 274559
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Mercury .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for mercury is the probable effect concentration (PEC) of 1.06 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 145505, Mercury
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 274580
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Mercury .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for mercury is the probable effect concentration (PEC) of 1.06 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144173
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Naphthalene
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144173, Naphthalene
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 274642
 
Pollutant: Naphthalene
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Naphthalene .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for naphthalene is the probable effect concentration (PEC) of 561 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144173, Naphthalene
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 274597
 
Pollutant: Naphthalene
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Naphthalene .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for naphthalene is the probable effect concentration (PEC) of 561 ug/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144174
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Nickel
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144174, Nickel
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 274810
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2013 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Nickel .
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for nickel is the probable effect concentration (PEC) of 48.6 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00271 (Tributary of Sycamore Creek at 3016 Deer Meadow Dr, Danville-207R00271).
Temporal Representation: Data for this waterbody were collected over the date range 2013-07-09 to 2013-07-09
Environmental Conditions:
QAPP Information: EOA, Inc.. 2012. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144174, Nickel
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 274852
 
Pollutant: Nickel
LOE Subgroup: Pollutant-Sediment
Matrix: Sediment
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Nickel .
Data Reference: Field, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Section 3.3.18 of the San Francisco Bay Region's Basin Plan contains the narrative toxicity objective stating that all waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline: The evaluation guideline for nickel is the probable effect concentration (PEC) of 48.6 mg/kg dry weight (MacDonald et al., 2000a).
Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31
 
Spatial Representation: Data were collected from 1 station(s). Station Code(s): 207R00891 (Green Valley Creek).
Temporal Representation: Data for this waterbody were collected over the date range 2015-07-07 to 2015-07-07
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
 
DECISION ID
144175
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
Pollutant: Oxygen, Dissolved
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
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:
 
 
Line of Evidence (LOE) for Decision ID 144175, Oxygen, Dissolved
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 286052
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2014 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.)
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R00379 (Green Valley Creek, West Branch).
Temporal Representation: The samples were collected between the dates of 2014-04-21 and 2014-04-21
Environmental Conditions:
QAPP Information: EOA, Inc.. 2014. Creek Status Monitoring Program Quality Assurance Project Plan.
QAPP Information Reference(s): Creek Status Monitoring Program Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 144175, Oxygen, Dissolved
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 286522
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2020 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 2.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Dissolved oxygen objectives for waters designated as warm water habitat shall be of a 5.0 mg/l minimum. (Water Quality Control Plan, San Francisco Bay Basin, Chapter III Water Quality Objectives.)
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 207R02884 (Sycamore Creek, 75m N of Barrenger Drive and Chadbourne Drive intersection curve).
Temporal Representation: The samples were collected between the dates of 2020-06-08 and 2020-06-08
Environmental Conditions:
QAPP Information: EOA, Inc.. 2000. Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project.
QAPP Information Reference(s): Creek Status and Pesticides & Toxicity Monitoring Quality Assurance Project
 
Line of Evidence (LOE) for Decision ID 144175, Oxygen, Dissolved
Region 2     
San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek)
 
LOE ID: 286343
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2017 data for San Ramon Creek subwatershed (Contra Costa County, tributary to Walnut Creek) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved.
Data Reference: Field, Habitat, Toxicity, WQ data from the California Environmental Data Exchange