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

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name: Santa Anita Wash (Peck Road Park to Elkins Ave.)
Water Body ID: CAR4123100020210715073524
Water Body Type: River & Stream
 
DECISION ID
140717
Region 4     
Santa Anita Wash (Peck Road Park to Elkins Ave.)
 
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 140717, Chlordane
Region 4     
Santa Anita Wash (Peck Road Park to Elkins Ave.)
 
LOE ID: 252990
 
Pollutant: Chlordane
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 LA County MS4 data for Santa Anita Wash (Peck Road Park to Elkins Ave.) to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Total Chlordane.
Data Reference: WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The chlordane criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0043 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: RHSGRSANDD (Santa Anita Wash ramp between Daines Drive and Peck Road Park Lake).
Temporal Representation: The samples were collected between the dates of 2018-11-22 and 2018-11-22
Environmental Conditions:
QAPP Information: Municipal Separate Storm Sewer System (MS4)
QAPP Information Reference(s): Municipal Separate Storm Sewer System (MS4)
 
 
DECISION ID
140718
Region 4     
Santa Anita Wash (Peck Road Park to Elkins Ave.)
 
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 140718, Chloride
Region 4     
Santa Anita Wash (Peck Road Park to Elkins Ave.)
 
LOE ID: 251989
 
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 LA County MS4 data for Santa Anita Wash (Peck Road Park to Elkins Ave.) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chloride.
Data Reference: WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan for the Los Angeles Region states that: Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
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: RHSGRSANDD (Santa Anita Wash ramp between Daines Drive and Peck Road Park Lake).
Temporal Representation: The samples were collected between the dates of 2015-10-04 and 2015-10-04
Environmental Conditions:
QAPP Information: Municipal Separate Storm Sewer System (MS4)
QAPP Information Reference(s): Municipal Separate Storm Sewer System (MS4)
 
 
DECISION ID
140719
Region 4     
Santa Anita Wash (Peck Road Park to Elkins Ave.)
 
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 140719, Dieldrin
Region 4     
Santa Anita Wash (Peck Road Park to Elkins Ave.)
 
LOE ID: 252199
 
Pollutant: Dieldrin
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 LA County MS4 data for Santa Anita Wash (Peck Road Park to Elkins Ave.) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Dieldrin.
Data Reference: WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The dieldrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 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: RHSGRSANDD (Santa Anita Wash ramp between Daines Drive and Peck Road Park Lake).
Temporal Representation: The samples were collected between the dates of 2018-11-22 and 2018-11-22
Environmental Conditions:
QAPP Information: Municipal Separate Storm Sewer System (MS4)
QAPP Information Reference(s): Municipal Separate Storm Sewer System (MS4)
 
 
DECISION ID
149853
Region 4     
Santa Anita Wash (Peck Road Park to Elkins Ave.)
 
Pollutant: Nitrogen, Nitrate
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 149853, Nitrogen, Nitrate
Region 4     
Santa Anita Wash (Peck Road Park to Elkins Ave.)
 
LOE ID: 302547
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed LA County MS4 data for Santa Anita Wash (Peck Road Park to Elkins Ave.) to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Nitrate as N.
Data Reference: WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan for the Los Angeles Region (page 3-34) states that: Waters shall not exceed 10 mg/L as nitrate-nitrogen (NO3-N).
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: RHSGRSANDD (Santa Anita Wash ramp between Daines Drive and Peck Road Park Lake).
Temporal Representation: The samples were collected between the dates of 2015-10-04 and 2019-11-27
Environmental Conditions:
QAPP Information: Municipal Separate Storm Sewer System (MS4)
QAPP Information Reference(s): Municipal Separate Storm Sewer System (MS4)
 
 
DECISION ID
140720
Region 4     
Santa Anita Wash (Peck Road Park to Elkins Ave.)
 
Pollutant: Lead
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: A Source Unknown
Expected TMDL Completion Date: 2037
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

1 lines of evidence are available in the administrative record to assess this pollutant.
2 of the 6 samples exceed the criteria.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. 2 of 6 samples exceed the criteria and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 140720, Lead
Region 4     
Santa Anita Wash (Peck Road Park to Elkins Ave.)
 
LOE ID: 252607
 
Pollutant: Lead
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 6
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed LA County MS4 data for Santa Anita Wash (Peck Road Park to Elkins Ave.) to determine beneficial use support and the results are as follows: 2 of the 6 samples exceeded the water quality threshold for Lead. Although a total of 13 samples were collected, 7 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.
Data Reference: WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The dissolved lead criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 2.5 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 (RHSGRSANDD).
Temporal Representation: Data for this waterbody was collected over the date range 2015-10-04 to 2019-11-27
Environmental Conditions:
QAPP Information: Municipal Separate Storm Sewer System (MS4)
QAPP Information Reference(s): Municipal Separate Storm Sewer System (MS4)
 
 
DECISION ID
150329
Region 4     
Santa Anita Wash (Peck Road Park to Elkins Ave.)
 
Pollutant: Indicator Bacteria
Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: A Source Unknown
TMDL Name: Los Angeles River Pathogens (15)
TMDL Project Code: 238
Date TMDL Approved by USEPA: 10/23/2012
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.3 and 3.11 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this waterbody-pollutant combination. Because a statistically sufficient number of geomean samples were not available, attainment of the bacteria objective was determined based only on the STV per the situation-specific weight of evidence approach outlined in Section 3.11 of the Listing Policy.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. 28 of 30 samples exceed the statistical threshold value for E. coli and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 150329, Indicator Bacteria
Region 4     
Santa Anita Wash (Peck Road Park to Elkins Ave.)
 
LOE ID: 302980
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: STV
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 29
Number of Exceedances: 27
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed LA County MS4 data for Santa Anita Wash (Peck Road Park to Elkins Ave.) to determine beneficial use support and the results are as follows: 27 of the 29 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.
Data Reference: WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective to protect the REC-1 beneficial use where the salinity is less than 1 parts per thousand 95 percent or more of the time applies a statistical threshold value to E. coli of 320 cfu/100 mL, not to be exceeded by more than 10 percent of samples within a calendar month (ISWEBE 2018).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): RHSGRSANDD (Santa Anita Wash ramp between Daines Drive and Peck Road Park Lake).
Temporal Representation: The samples were collected between the days of 2015-09-21 and 2019-11-27 .
Environmental Conditions:
QAPP Information: Municipal Separate Storm Sewer System (MS4)
QAPP Information Reference(s): Municipal Separate Storm Sewer System (MS4)
 
Line of Evidence (LOE) for Decision ID 150329, Indicator Bacteria
Region 4     
Santa Anita Wash (Peck Road Park to Elkins Ave.)
 
LOE ID: 303017
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: STV
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed LA County MS4 data for Santa Anita Wash (Peck Road Park to Elkins Ave.) to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.
Data Reference: WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective to protect the REC-1 beneficial use where the salinity is less than 1 parts per thousand 95 percent or more of the time applies a statistical threshold value to E. coli of 320 cfu/100 mL, not to be exceeded by more than 10 percent of samples within a calendar month (ISWEBE 2018).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): RHSGRSAN_DD (NA).
Temporal Representation: The samples were collected between the days of 2016-07-28 and 2016-07-28 .
Environmental Conditions:
QAPP Information: Municipal Separate Storm Sewer System (MS4)
QAPP Information Reference(s): Municipal Separate Storm Sewer System (MS4)