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

Supporting Information

Regional Board 9 - San Diego Region

Water Body Name: Unknown tributary to Agua Hedionda Creek (San Diego County)
Water Body ID: CAR9043100020191211032370
Water Body Type: River & Stream
 
DECISION ID
115085
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
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 115085, Alkalinity as CaCO3
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
LOE ID: 139786
 
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 SMC Regional Watershed Monitoring data for Unknown tributary to Agua Hedionda Creek (San Diego County) 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, San Diego Basin).
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin
 
Evaluation Guideline: The CCC of 20mg/L is a minimum value except where alkalinity is naturally lower, in which case the criterion cannot be lower than 25% of the natural level (USEPA National Recommended Water Quality Criteria Aquatic Life)
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
Spatial Representation: The samples were collected at 1 monitoring site (904M21720)
Temporal Representation: The samples were collected between the dates of 2015-06-25 and 2015-06-25
Environmental Conditions:
QAPP Information: Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.
QAPP Information Reference(s): Regional Monitoring of Southern California's Coastal Watersheds
QAPP Information Reference(s): Bioassessment Survey of the Stormwater Monitoring Coalition
 
 
DECISION ID
126477
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
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.

One line(s) of evidence evaluating benthic-macroinvertebrate bioassessment data is/are available in the administrative record to assess this indicator. One of one benthic-macroinvertebrate samples exceed the California Stream Condition Index (CSCI) impairment threshold. However, a minimum of two benthic-macroinvertebrate samples 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. One of one 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 because applicable water quality standards are not being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 126477, Benthic Community Effects
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
LOE ID: 215854
 
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 904M21720 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.7638 to 0.7638 .
Data Reference: California Stream Condition Index Scores for the 2020 Integrated Report
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant or animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analysis of species diversity, population density, growth anomalies, bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board. Region 9 Basin Plan.
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin
 
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 (Rhen, 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 904M21720
Temporal Representation: Samples were collected from 6/25/2015 to 6/25/2015.
Environmental Conditions:
QAPP Information: The data was collected under a permit required receiving waters monitoring and reporting program
QAPP Information Reference(s): Quality Assurance Project Plan for Southern California Regional Watershed Monitoring Program Bioassessment, Version 1.0, and Freshwater Bioassessment from Weston Solutions.
 
 
DECISION ID
115078
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
Pollutant: Chloride
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 115078, Chloride
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
LOE ID: 141243
 
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 SMC Regional Watershed Monitoring data for Unknown tributary to Agua Hedionda Creek (San Diego County) to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Chloride water quality threshold in this HSA is 250 mg/L, and this concentration is not to be exceeded more than 10% of the time during any one year period (Basin Plan, Table 3-2).
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (904M21720)
Temporal Representation: The samples were collected between the dates of 2015-06-22 and 2015-06-22
Environmental Conditions:
QAPP Information: Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.
QAPP Information Reference(s): Regional Monitoring of Southern California's Coastal Watersheds
QAPP Information Reference(s): Bioassessment Survey of the Stormwater Monitoring Coalition
 
Line of Evidence (LOE) for Decision ID 115078, Chloride
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
LOE ID: 141001
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Agricultural Supply
 
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 SMC Regional Watershed Monitoring data for Unknown tributary to Agua Hedionda Creek (San Diego County) to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Chloride water quality threshold in this HSA is 250 mg/L, and this concentration is not to be exceeded more than 10% of the time during any one year period (Basin Plan, Table 3-2).
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (904M21720)
Temporal Representation: The samples were collected between the dates of 2015-06-22 and 2015-06-22
Environmental Conditions:
QAPP Information: Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.
QAPP Information Reference(s): Regional Monitoring of Southern California's Coastal Watersheds
QAPP Information Reference(s): Bioassessment Survey of the Stormwater Monitoring Coalition
 
Line of Evidence (LOE) for Decision ID 115078, Chloride
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
LOE ID: 141308
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
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 SMC Regional Watershed Monitoring data for Unknown tributary to Agua Hedionda Creek (San Diego County) to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Chloride water quality threshold in this HSA is 250 mg/L, and this concentration is not to be exceeded more than 10% of the time during any one year period (Basin Plan, Table 3-2).
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (904M21720)
Temporal Representation: The samples were collected between the dates of 2015-06-22 and 2015-06-22
Environmental Conditions:
QAPP Information: Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.
QAPP Information Reference(s): Regional Monitoring of Southern California's Coastal Watersheds
QAPP Information Reference(s): Bioassessment Survey of the Stormwater Monitoring Coalition
 
 
DECISION ID
115079
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
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 115079, Nitrate/Nitrite (Nitrite + Nitrate as N)
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
LOE ID: 143938
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
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 SMC Regional Watershed Monitoring data for Unknown tributary to Agua Hedionda Creek (San Diego County) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Nitrate + Nitrite as N.
Data Reference: Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California Maximum Contaminant Level for nitrate + nitrite (as N) is 10.0 mg/L (Title 22 of the California Code of Regulations).
Objective/Criterion Reference: Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (904M21720)
Temporal Representation: The samples were collected between the dates of 2015-06-22 and 2015-06-22
Environmental Conditions:
QAPP Information: Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.
QAPP Information Reference(s): Regional Monitoring of Southern California's Coastal Watersheds
QAPP Information Reference(s): Bioassessment Survey of the Stormwater Monitoring Coalition
 
 
DECISION ID
127262
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
Pollutant: Nitrogen
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 127262, Nitrogen
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
LOE ID: 144228
 
Pollutant: Total Nitrogen as N
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 SMC Regional Watershed Monitoring data for Unknown tributary to Agua Hedionda Creek (San Diego County) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Nitrogen, Total.
Data Reference: Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Concentrations of nitrogen and phosphorus, by themselves or in combination with other nutrients, shall be maintained at levels below those which stimulate algae and emergent plant growth. A desired goal in order to prevent plant nuisance in streams and other flowing waters appears to be 0.1 mg/L total P. Analogous threshold values have not been set for nitrogen compounds; however, natural ratios of nitrogen to phosphorus are to be determined by surveillance and monitoring and upheld. If data are lacking, a ratio of N:P = 10:1, on a weight to weight basis shall be used (Water Quality Control Plan, San Diego Basin).
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (904M21720)
Temporal Representation: The samples were collected between the dates of 2015-06-22 and 2015-06-22
Environmental Conditions:
QAPP Information: Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.
QAPP Information Reference(s): Regional Monitoring of Southern California's Coastal Watersheds
QAPP Information Reference(s): Bioassessment Survey of the Stormwater Monitoring Coalition
 
 
DECISION ID
115080
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
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 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 115080, Oxygen, Dissolved
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
LOE ID: 144644
 
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 SMC Regional Watershed Monitoring data for Unknown tributary to Agua Hedionda Creek (San Diego County) 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Dissolved oxygen levels shall not be less than 5.0 mg/l in inland surface waters with the WARM beneficial use designated (Water Quality Control Plan, San Diego Basin).
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (904M21720)
Temporal Representation: The samples were collected between the dates of 2015-06-25 and 2015-06-25
Environmental Conditions:
QAPP Information: Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.
QAPP Information Reference(s): Regional Monitoring of Southern California's Coastal Watersheds
QAPP Information Reference(s): Bioassessment Survey of the Stormwater Monitoring Coalition
 
 
DECISION ID
115082
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
Pollutant: Phosphorus
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 115082, Phosphorus
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
LOE ID: 145825
 
Pollutant: Phosphorus
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 SMC Regional Watershed Monitoring data for Unknown tributary to Agua Hedionda Creek (San Diego County) to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Phosphorus as P.
Data Reference: Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Concentrations of nitrogen and phosphorus, by themselves or in combination with other nutrients, shall be maintained at levels below those which stimulate algae and emergent plant growth. A desired goal in order to prevent plant nuisance in streams and other flowing waters appears to be 0.1 mg/L total P. Analogous threshold values have not been set for nitrogen compounds; however, natural ratios of nitrogen to phosphorus are to be determined by surveillance and monitoring and upheld. If data are lacking, a ratio of N:P = 10:1, on a weight to weight basis shall be used (Water Quality Control Plan, San Diego Basin).
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (904M21720)
Temporal Representation: The samples were collected between the dates of 2015-06-22 and 2015-06-22
Environmental Conditions:
QAPP Information: Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.
QAPP Information Reference(s): Regional Monitoring of Southern California's Coastal Watersheds
QAPP Information Reference(s): Bioassessment Survey of the Stormwater Monitoring Coalition
 
 
DECISION ID
127449
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
Pollutant: Specific Conductivity
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 127449, Specific Conductivity
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
LOE ID: 146745
 
Pollutant: Specific Conductivity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
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 SMC Regional Watershed Monitoring data for Unknown tributary to Agua Hedionda Creek (San Diego County) to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for SpecificConductivity.
Data Reference: Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Table 64449-A of section 64449 of Title 22 of the California Code of Regulations (Secondary Maximum Contaminant Levels, Consumer Acceptance Limits) which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Secondary MCL for specific conductance is 900 uS/cm (Title 22 California Code of Regulations).
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (904M21720)
Temporal Representation: The samples were collected between the dates of 2015-06-25 and 2015-06-25
Environmental Conditions:
QAPP Information: Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.
QAPP Information Reference(s): Regional Monitoring of Southern California's Coastal Watersheds
QAPP Information Reference(s): Bioassessment Survey of the Stormwater Monitoring Coalition
 
 
DECISION ID
115083
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
Pollutant: Sulfates
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 115083, Sulfates
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
LOE ID: 146790
 
Pollutant: Sulfates
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
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 SMC Regional Watershed Monitoring data for Unknown tributary to Agua Hedionda Creek (San Diego County) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Sulfate.
Data Reference: Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Sulfate water quality threshold in this HSA is 250 mg/L, and this concentration is not to be exceeded more than 10% of the time during any one year period (Basin Plan, Table 3-2).
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (904M21720)
Temporal Representation: The samples were collected between the dates of 2015-06-22 and 2015-06-22
Environmental Conditions:
QAPP Information: Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.
QAPP Information Reference(s): Regional Monitoring of Southern California's Coastal Watersheds
QAPP Information Reference(s): Bioassessment Survey of the Stormwater Monitoring Coalition
 
 
DECISION ID
115084
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
Pollutant: Turbidity
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
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 115084, Turbidity
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
LOE ID: 147649
 
Pollutant: Turbidity
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 SMC Regional Watershed Monitoring data for Unknown tributary to Agua Hedionda Creek (San Diego County) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Turbidity.
Data Reference: Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Turbidity water quality threshold in this HSA is 20 NTU, and this level is not to be exceeded more than 10% of the time during any one year period (Basin Plan, Table 3-2).
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (904M21720)
Temporal Representation: The samples were collected between the dates of 2015-06-25 and 2015-06-25
Environmental Conditions:
QAPP Information: Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.
QAPP Information Reference(s): Regional Monitoring of Southern California's Coastal Watersheds
QAPP Information Reference(s): Bioassessment Survey of the Stormwater Monitoring Coalition
 
Line of Evidence (LOE) for Decision ID 115084, Turbidity
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
LOE ID: 147454
 
Pollutant: Turbidity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
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 SMC Regional Watershed Monitoring data for Unknown tributary to Agua Hedionda Creek (San Diego County) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Turbidity.
Data Reference: Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Secondary California Maximum Contaminant Level for Turbidity is 5 NTU (Title 22 of the California Code of Regulations).
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (904M21720)
Temporal Representation: The samples were collected between the dates of 2015-06-25 and 2015-06-25
Environmental Conditions:
QAPP Information: Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.
QAPP Information Reference(s): Regional Monitoring of Southern California's Coastal Watersheds
QAPP Information Reference(s): Bioassessment Survey of the Stormwater Monitoring Coalition
 
 
DECISION ID
115081
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
Pollutant: pH
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 115081, pH
Region 9     
Unknown tributary to Agua Hedionda Creek (San Diego County)
 
LOE ID: 145379
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
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 SMC Regional Watershed Monitoring data for Unknown tributary to Agua Hedionda Creek (San Diego County) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH.
Data Reference: Field, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: In inland surface waters the pH shall not be depressed below 6.5 nor raised above 8.5.
Objective/Criterion Reference: Water Quality Control Plan for the San Diego Basin
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site (904M21720)
Temporal Representation: The samples were collected between the dates of 2015-06-25 and 2015-06-25
Environmental Conditions:
QAPP Information: Weston Solutions, Inc.. 2007. Regional Monitoring of Southern California's Coastal Watersheds., Weston Solutions, Inc.. 2019. Bioassessment Survey of the Stormwater Monitoring Coalition.
QAPP Information Reference(s): Regional Monitoring of Southern California's Coastal Watersheds
QAPP Information Reference(s): Bioassessment Survey of the Stormwater Monitoring Coalition