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

Supporting Information

Regional Board 2 - San Francisco Bay Region

Water Body Name: Atherton Creek (San Mateo)
Water Body ID: CAR2044004020210406047019
Water Body Type: River & Stream
 
DECISION ID
143882
Region 2     
Atherton Creek (San Mateo)
 
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: 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 143882, Alkalinity as CaCO3
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 276972
 
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 Atherton Creek (San Mateo) 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: 204R01448 (Atherton Creek at 354 Walsh Rd).
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
 
 
DECISION ID
150855
Region 2     
Atherton Creek (San Mateo)
 
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: 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 150855, Ammonia
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 278384
 
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 Atherton Creek (San Mateo) 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: 204R02611 (Atherton Creek at Barry Lane).
Temporal Representation: The samples were collected between the dates of 2017-05-23 and 2017-05-23
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 150855, Ammonia
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 280175
 
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 Atherton Creek (San Mateo) 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: 204R02611 (Atherton Creek at Barry Lane).
Temporal Representation: The samples were collected between the dates of 2017-05-23 and 2017-05-23
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 150855, Ammonia
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 279598
 
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 Atherton Creek (San Mateo) 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: 204R03240 (Atherton Creek below Hwy 280).
Temporal Representation: The samples were collected between the dates of 2017-05-23 and 2017-05-23
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 150855, Ammonia
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 279939
 
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 Atherton Creek (San Mateo) 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: 204R01448 (Atherton Creek at 354 Walsh Rd).
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 150855, Ammonia
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 279573
 
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 Atherton Creek (San Mateo) 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: 204ATH010 (Atherton Creek upstream El Camino Real).
Temporal Representation: The samples were collected between the dates of 2017-01-09 and 2017-01-09
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 150855, Ammonia
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 279408
 
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 WY2019 data for Atherton Creek (San Mateo) 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: 204R04600 (Atherton Creek u/s Broadacres Rd).
Temporal Representation: The samples were collected between the dates of 2019-07-31 and 2019-07-31
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 150855, Ammonia
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 279597
 
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 Atherton Creek (San Mateo) 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: 204ATH050 (Atherton Creek downstream Valley Court).
Temporal Representation: The samples were collected between the dates of 2017-01-09 and 2017-01-09
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 150855, Ammonia
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 279572
 
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 WY2019 data for Atherton Creek (San Mateo) 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: 204R03635 (Atherton Creek u/s Isabella Ave).
Temporal Representation: The samples were collected between the dates of 2019-06-10 and 2019-06-10
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 150855, Ammonia
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 277796
 
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 WY2019 data for Atherton Creek (San Mateo) 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: 204R03635 (Atherton Creek u/s Isabella Ave).
Temporal Representation: The samples were collected between the dates of 2019-06-10 and 2019-06-10
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 150855, Ammonia
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 278182
 
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 Atherton Creek (San Mateo) 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: 204R01448 (Atherton Creek at 354 Walsh Rd).
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 150855, Ammonia
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 277526
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
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 WY2019 data for Atherton Creek (San Mateo) to determine beneficial use support and results are as follows: 0 of 2 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: 204R04600 (Atherton Creek u/s Broadacres Rd).
Temporal Representation: The samples were collected between the dates of 2019-06-10 and 2019-07-31
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 150855, Ammonia
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 277935
 
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 Atherton Creek (San Mateo) 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: 204ATH010 (Atherton Creek upstream El Camino Real).
Temporal Representation: The samples were collected between the dates of 2017-01-09 and 2017-01-09
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 150855, Ammonia
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 277659
 
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 Atherton Creek (San Mateo) 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: 204R03240 (Atherton Creek below Hwy 280).
Temporal Representation: The samples were collected between the dates of 2017-05-23 and 2017-05-23
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 150855, Ammonia
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 277636
 
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 Atherton Creek (San Mateo) 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: 204ATH050 (Atherton Creek downstream Valley Court).
Temporal Representation: The samples were collected between the dates of 2017-01-09 and 2017-01-09
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
 
 
DECISION ID
143859
Region 2     
Atherton Creek (San Mateo)
 
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: 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 143859, Arsenic
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 269998
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
151839
Region 2     
Atherton Creek (San Mateo)
 
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 sections 3.9 of the Listing Policy. Under section 3.9, additional lines of evidence (LOEs) associating the Benthic Community Effects decision with a water or sediment concentration of pollutants other than benthic-macroinvertebrate bioassessment or habitat assessment LOEs are necessary to place a water body on the 303(d) List for Benthic Community Effects.

Three line(s) of evidence evaluating benthic-macroinvertebrate bioassessment data is/are available in the administrative record to assess this indicator. Three of three benthic-macroinvertebrate samples exceed the California Stream Condition Index (CSCI) impairment threshold. However, a minimum of two benthic-macroinvertebrate samples and an additional indicator pollutant are needed to assess listing status.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing Benthic Community Effects in this waterbody segment on the CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Three of three benthic-macroinvertebrate bioassessment samples had CSCI scores below 0.79. The available information is insufficient to determine whether the waterbody/pollutant combination should be placed on the 303(d) List of impaired waters at this time.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 151839, Benthic Community Effects
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 306631
 
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 204R01448 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.400787 to 0.400787.
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 204R01448.
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 151839, Benthic Community Effects
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 306632
 
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 204R02611 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.425858816 to 0.425858816.
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 204R02611.
Temporal Representation: Samples were collected from 5/23/2017 to 5/23/2017.
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 151839, Benthic Community Effects
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 306633
 
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 204R03240 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.411966458 to 0.411966458.
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 204R03240.
Temporal Representation: Samples were collected from 5/23/2017 to 5/23/2017.
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
 
 
DECISION ID
143880
Region 2     
Atherton Creek (San Mateo)
 
Pollutant: Bifenthrin
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 143880, Bifenthrin
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 270360
 
Pollutant: Bifenthrin
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 Atherton Creek (San Mateo) to determine beneficial use support and the results are as follows: 0 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143860
Region 2     
Atherton Creek (San Mateo)
 
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: 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 143860, Cadmium
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 270479
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143861
Region 2     
Atherton Creek (San Mateo)
 
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 143861, Chlordane
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 270967
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143862
Region 2     
Atherton Creek (San Mateo)
 
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: 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 143862, Chloride
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 281176
 
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 WY2019 data for Atherton Creek (San Mateo) 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: 204R04600 (Atherton Creek u/s Broadacres Rd).
Temporal Representation: The samples were collected between the dates of 2019-06-10 and 2019-06-10
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 143862, Chloride
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 281405
 
Pollutant: Chloride
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 WY2017 data for Atherton Creek (San Mateo) to determine beneficial use support and results are as follows: 1 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: 204R03240 (Atherton Creek below Hwy 280).
Temporal Representation: The samples were collected between the dates of 2017-05-23 and 2017-05-23
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 143862, Chloride
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 281175
 
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 Atherton Creek (San Mateo) 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: 204R02611 (Atherton Creek at Barry Lane).
Temporal Representation: The samples were collected between the dates of 2017-05-23 and 2017-05-23
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 143862, Chloride
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 281010
 
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 WY2019 data for Atherton Creek (San Mateo) 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: 204R03635 (Atherton Creek u/s Isabella Ave).
Temporal Representation: The samples were collected between the dates of 2019-06-10 and 2019-06-10
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 143862, Chloride
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 281404
 
Pollutant: Chloride
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 WY2015 data for Atherton Creek (San Mateo) to determine beneficial use support and results are as follows: 1 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: 204R01448 (Atherton Creek at 354 Walsh Rd).
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
 
 
DECISION ID
143863
Region 2     
Atherton Creek (San Mateo)
 
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.

Although there was a sufficient number of samples to assess total chlorine, this water body was given a use rating of Insufficient Information and a Do Not List decision. First, data were collected with field instruments that do not have the sensitivity to detect low levels of total chlorine to assess the freshwater water quality objectives of 11 ug/L and 19 ug/L. Secondly, most of the data were collected only once for a given site, and the data were not collected with the purpose of assessing chlorine levels in the water body. A more appropriate sampling to determine water quality impacts of chlorine might be conducted for future Integrated Report assessments.
 
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 143863, Chlorine
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 282542
 
Pollutant: Chlorine
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 WY2017 data for Atherton Creek (San Mateo) to determine beneficial use support and results are as follows: 1 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: 204R02611 (Atherton Creek at Barry Lane).
Temporal Representation: The samples were collected between the dates of 2017-05-23 and 2017-05-23
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 143863, Chlorine
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 282426
 
Pollutant: Chlorine
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 WY2017 data for Atherton Creek (San Mateo) to determine beneficial use support and results are as follows: 1 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: 204R03240 (Atherton Creek below Hwy 280).
Temporal Representation: The samples were collected between the dates of 2017-05-23 and 2017-05-23
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 143863, Chlorine
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 282592
 
Pollutant: Chlorine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed BASMAA RMC Monitoring in WY2015 data for Atherton Creek (San Mateo) to determine beneficial use support and results are as follows: 2 of 2 samples exceeded the water quality threshold for Chlorine, Total Residual.
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 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: 204R01448 (Atherton Creek at 354 Walsh Rd).
Temporal Representation: The samples were collected between the dates of 2015-04-22 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
 
 
DECISION ID
143886
Region 2     
Atherton Creek (San Mateo)
 
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: 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 143886, Chromium
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 271141
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143864
Region 2     
Atherton Creek (San Mateo)
 
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: 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 143864, Chrysene (C1-C4)
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 271175
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143865
Region 2     
Atherton Creek (San Mateo)
 
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: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 143865, Copper
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 271519
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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 143865, Copper
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 283289
 
Pollutant: Copper
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 BASMAA RMC Monitoring in WY2017 data for Atherton Creek (San Mateo) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold 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: The dissolved copper criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 9 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 204ATH010 (Atherton Creek upstream El Camino Real).
Temporal Representation: The samples were collected between the dates of 2017-01-09 and 2017-01-09
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 143865, Copper
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 283286
 
Pollutant: Copper
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 BASMAA RMC Monitoring in WY2017 data for Atherton Creek (San Mateo) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold 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: The dissolved copper criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 9 ug/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: 204ATH050 (Atherton Creek downstream Valley Court).
Temporal Representation: The samples were collected between the dates of 2017-01-09 and 2017-01-09
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
 
 
DECISION ID
143883
Region 2     
Atherton Creek (San Mateo)
 
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: 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 143883, Cyfluthrin
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 271841
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143885
Region 2     
Atherton Creek (San Mateo)
 
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: 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 143885, Cyhalothrin, Lambda
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 271933
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143881
Region 2     
Atherton Creek (San Mateo)
 
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: 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 143881, Cypermethrin
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 272269
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
145712
Region 2     
Atherton Creek (San Mateo)
 
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: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 145712, DDD (Dichlorodiphenyldichloroethane)
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 272136
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
148162
Region 2     
Atherton Creek (San Mateo)
 
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: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 148162, DDE (Dichlorodiphenyldichloroethylene)
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 272081
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
148245
Region 2     
Atherton Creek (San Mateo)
 
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 148245, DDT (Dichlorodiphenyltrichloroethane)
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 272486
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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 148245, DDT (Dichlorodiphenyltrichloroethane)
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 276218
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143884
Region 2     
Atherton Creek (San Mateo)
 
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: 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 143884, Deltamethrin
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 272340
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143866
Region 2     
Atherton Creek (San Mateo)
 
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: 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 143866, Dieldrin
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 272954
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143867
Region 2     
Atherton Creek (San Mateo)
 
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: 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 143867, Endrin
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 272771
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143887
Region 2     
Atherton Creek (San Mateo)
 
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: 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 143887, Esfenvalerate/Fenvalerate
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 273244
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143868
Region 2     
Atherton Creek (San Mateo)
 
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: 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 143868, Fluoranthene
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 273479
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143869
Region 2     
Atherton Creek (San Mateo)
 
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: 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 143869, Fluorene
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 273406
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143870
Region 2     
Atherton Creek (San Mateo)
 
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: 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 143870, Lead
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 274169
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143871
Region 2     
Atherton Creek (San Mateo)
 
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: 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 143871, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 273814
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
154567
Region 2     
Atherton Creek (San Mateo)
 
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: 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 154567, Mercury
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 274313
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143872
Region 2     
Atherton Creek (San Mateo)
 
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: 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 143872, Naphthalene
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 274718
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143873
Region 2     
Atherton Creek (San Mateo)
 
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: 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 143873, Nickel
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 274785
 
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 Atherton Creek (San Mateo) 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143874
Region 2     
Atherton Creek (San Mateo)
 
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: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 143874, Oxygen, Dissolved
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 285099
 
Pollutant: Oxygen, Dissolved
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 WY2019 data for Atherton Creek (San Mateo) to determine beneficial use support and results are as follows: 0 of 2 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: 204R04600 (Atherton Creek u/s Broadacres Rd).
Temporal Representation: The samples were collected between the dates of 2019-06-10 and 2019-07-31
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 143874, Oxygen, Dissolved
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 285546
 
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 Atherton Creek (San Mateo) 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: 204ATH010 (Atherton Creek upstream El Camino Real).
Temporal Representation: The samples were collected between the dates of 2017-01-09 and 2017-01-09
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 143874, Oxygen, Dissolved
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 285206
 
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 Atherton Creek (San Mateo) 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: 204ATH050 (Atherton Creek downstream Valley Court).
Temporal Representation: The samples were collected between the dates of 2017-01-09 and 2017-01-09
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 143874, Oxygen, Dissolved
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 285784
 
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 Atherton Creek (San Mateo) 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: 204R03240 (Atherton Creek below Hwy 280).
Temporal Representation: The samples were collected between the dates of 2017-05-23 and 2017-05-23
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 143874, Oxygen, Dissolved
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 285096
 
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 WY2019 data for Atherton Creek (San Mateo) 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: 204R03635 (Atherton Creek u/s Isabella Ave).
Temporal Representation: The samples were collected between the dates of 2019-06-10 and 2019-06-10
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 143874, Oxygen, Dissolved
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 284787
 
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 Atherton Creek (San Mateo) 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: 204R02611 (Atherton Creek at Barry Lane).
Temporal Representation: The samples were collected between the dates of 2017-05-23 and 2017-05-23
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 143874, Oxygen, Dissolved
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 285870
 
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 WY2015 data for Atherton Creek (San Mateo) 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, 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: 204R01448 (Atherton Creek at 354 Walsh Rd).
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
 
 
DECISION ID
148802
Region 2     
Atherton Creek (San Mateo)
 
Pollutant: PAHs (Polycyclic Aromatic Hydrocarbons)
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 148802, PAHs (Polycyclic Aromatic Hydrocarbons)
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 275046
 
Pollutant: PAHs (Polycyclic Aromatic Hydrocarbons)
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 Atherton Creek (San Mateo) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for PAHs (Polycyclic Aromatic Hydrocarbons) .
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 PAHs is the probable effect concentration (PEC) of 22800 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143888
Region 2     
Atherton Creek (San Mateo)
 
Pollutant: Permethrin
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 143888, Permethrin
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 275298
 
Pollutant: Permethrin
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 Atherton Creek (San Mateo) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Permethrin, 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 permethrin is the median lethal concentration (LC50) of 8.9 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 8.9 ug/g is the geometric mean of LC50 values for permethrin (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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143875
Region 2     
Atherton Creek (San Mateo)
 
Pollutant: Phenanthrene
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 143875, Phenanthrene
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 275519
 
Pollutant: Phenanthrene
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 Atherton Creek (San Mateo) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Phenanthrene .
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 phenanthrene is the probable effect concentration (PEC) of 1170 ug/kg dry weight (MacDonald et al.).
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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143876
Region 2     
Atherton Creek (San Mateo)
 
Pollutant: 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: 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 143876, Pyrene
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 275721
 
Pollutant: 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 Atherton Creek (San Mateo) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for 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 pyrene is the probable effect concentration (PEC) of 1520 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143879
Region 2     
Atherton Creek (San Mateo)
 
Pollutant: Pyrethroids
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 143879, Pyrethroids
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 276080
 
Pollutant: Pyrethroids
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 Atherton Creek (San Mateo) to determine beneficial use support and the results are as follows: 0 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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
143877
Region 2     
Atherton Creek (San Mateo)
 
Pollutant: Toxicity
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 143877, Toxicity
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 268754
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Sediment
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: 0 of the 1 samples collected by BASMAA RMC Monitoring in WY2015 for Atherton Creek (San Mateo) 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 Survival, Hyalella azteca for Growth (wt/surv indiv).
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: 204R01448 ( Atherton Creek at 354 Walsh Rd ).
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 143877, Toxicity
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 268753
 
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 WY2015 for Atherton Creek (San Mateo) 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, Selenastrum capricornutum for Total Cell Count, Pimephales promelas for Survival, Ceriodaphnia dubia for Young/female, Hyalella azteca for Survival, Pimephales promelas for Biomass (wt/orig indiv). The following tests exhibited toxicity: Ceriodaphnia dubia for Young/female on 2015-02-06, Hyalella azteca for Survival on 2015-02-06.
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: 204R01448 ( Atherton Creek at 354 Walsh Rd ).
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
 
 
DECISION ID
143878
Region 2     
Atherton Creek (San Mateo)
 
Pollutant: Zinc
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 143878, Zinc
Region 2     
Atherton Creek (San Mateo)
 
LOE ID: 276404
 
Pollutant: Zinc
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 Atherton Creek (San Mateo) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Zinc .
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 zinc is the probable effect concentration (PEC) of 459 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): 204R01448 (Atherton Creek at 354 Walsh Rd).
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