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

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name: Aliso Canyon Wash
Water Body ID: CAR4052100019990201130918
Water Body Type: River & Stream
 
DECISION ID
68533
Region 4     
Aliso Canyon Wash
 
Pollutant: Diazinon
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the 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.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. One of six samples exceeded the DFG Diazinon acute hazard assessment criteria of 0.16 ug/l 1 hour average for the protection of aquatic life beneficial uses. Thisand this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
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: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current. The decision has not changed.
 
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 68533, Diazinon
Region 4     
Aliso Canyon Wash
 
LOE ID: 2502
 
Pollutant: Diazinon
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 6
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Numeric data generated from six (6) samples out of which one sample exceeded the DFG criteria (LACDPW, 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion:
Objective/Criterion Reference:
 
Evaluation Guideline: Numerical Diazinon guideline used to interpret Basin Plan narrative pesticide WQO. The numeric guideline used is 0.16 ug/l 1-hour average generated by DFG as a fresh water acute hazard assessment criteria for the protection of aquatic life (Siepman & Finlayson, 2000; Finlayson, 2004).
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: One sample site.
Temporal Representation: Six monthly samples, Five (5) taken during the wet season (11/08/2002-03/15/2003) and one (1) sample taken during the dry season (04/30/2003).
Environmental Conditions: Data age 1-2 years.
QAPP Information: Evaluation of Analytes and QA/QC Specifications for Monitoring Program
(Woodward-Clyde, 1996) Los Angeles County Department of Public Works.
QAPP Information Reference(s):
 
 
DECISION ID
68066
Region 4     
Aliso Canyon Wash
 
Pollutant: Zinc
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the Secondary MCL to protect MUN beneficial uses.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. No samples exceeded the Secondary MCL criterion of 5 mg/l for total zinc this and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
3. 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: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current. The decision has not changed.
 
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 68066, Zinc
Region 4     
Aliso Canyon Wash
 
LOE ID: 2501
 
Pollutant: Zinc
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Numeric data generated from five samples out of which no sample exceeded the secondary MCL guideline for zinc of 5 mg/l for protection MUN BUs (LACDPW, 2003).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Secondary MCL guideline for zinc of 5 mg/l shall not be exceeded to protect MUN beneficial uses in accordance with Title 22 of the California Code of regulation table 64449-A of section 64449.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: One sample site.
Temporal Representation: Five monthly samples, four (4) taken during the wet season (11/08/2002-03/15/2003) and one (1) sample taken during the dry season (04/30/2003).
Environmental Conditions: Age of data 1-2 years.
QAPP Information: Evaluation of Analytes and QA/QC Specifications for Monitoring Program
(Woodward-Clyde, 1996) Los Angeles County Department of Public Works.
QAPP Information Reference(s):
 
 
DECISION ID
68182
Region 4     
Aliso Canyon Wash
 
Pollutant: Copper
Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)(2016)
Revision Status Original
Sources: A Source Unknown
TMDL Name: Los Angeles River Metals (13)
TMDL Project Code: 237
Date TMDL Approved by USEPA: 10/29/2008
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: There is sufficient justification to place this waterbody/pollutant in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by USEPA, and is expected to result in attainment of the standard.

This conclusion is based on the staff findings that:
1. The Los Angeles River Metals TMDL was approved by USEPA on 10/29/2008.
2. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 68182, Copper
Region 4     
Aliso Canyon Wash
 
LOE ID: 2500
 
Pollutant: Copper
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Five samples, 2 exceeded the CTR criteria (LACDPW, 2003a).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: CTR criteria linked and applicable to Warm Fresh Water Habitat BUs.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: One sampling site.
Temporal Representation: Five monthly samples taken during the wet season (11/08/2002- 3/15/2003) and one sample taken during the dry season (04/30/2003).
Environmental Conditions: Data Age 1-2 years.
QAPP Information: Evaluation of Analytes and QA/QC Specifications for Monitoring Program
(Woodward-Clyde, 1996) Los Angeles County Department of Public Works.
QAPP Information Reference(s):
 
 
DECISION ID
68227
Region 4     
Aliso Canyon Wash
 
Pollutant: Indicator Bacteria
Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)(2016)
Revision Status Original
Sources: A Source Unknown
TMDL Name: Los Angeles River Pathogens (15)
TMDL Project Code: 238
Date TMDL Approved by USEPA: 03/23/2012
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: There is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by USEPA, and is expected to result in attainment of the standard.

This conclusion is based on the staff findings that:
1. The Los Angeles River Bacteria TMDL was approved by USEPA on 03/23/2012.
2. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 68227, Indicator Bacteria
Region 4     
Aliso Canyon Wash
 
LOE ID: 2497
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 6
Number of Exceedances: 6
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Six of 6 fecal coliform samples exceeded the single sample limit (LACDPW, 2003a).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Los Angeles RWQCB Basin Plan Amendment to Revise Bacteria Objectives for Waters Designated for Water Contact Recreation: fecal coliform density 200/100 ml 30-day geometric mean, 400/100 ml single sample limit.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: "Aliso Creek" Tributary Monitoring Station (TS01) is located at the southeast corner of the bridge on Saticoy over Aliso Canyon Wash in Reseda, California.
Temporal Representation: Five samples taken during the wet season (11/08/2002 - 3/15/2003) and one sample taken during the dry season (4/30/2003).
Environmental Conditions:
QAPP Information: QA/QC used by the Los Angeles County Department of Public Works - Evaluation of Analytes and QA/QC Specifications for Monitoring Program (Woodward-Clyde Consultants, 1996).
QAPP Information Reference(s):
 
 
DECISION ID
69691
Region 4     
Aliso Canyon Wash
 
Pollutant: Selenium
Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)(2016)
Revision Status Original
Sources: Nonpoint Source
TMDL Name: Los Angeles River Metals (13)
TMDL Project Code: 237
Date TMDL Approved by USEPA: 12/22/2005
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for listing under section 2.2 of the Listing Policy. Under this section of the Policy, a minimum of one line of evidence is needed to assess listing status.

The Los Angeles River and Tributaries Metals TMDL was approved by USEPA on 12/22/05.

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 in the Water Quality Limited Segments Being Addressed portion of the section 303(d) list.
 
Regional Board Decision Recommendation: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current. The decision has not changed.
 
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 69691, Selenium
Region 4     
Aliso Canyon Wash
 
LOE ID: 2503
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion:
Objective/Criterion Reference:
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation:
Temporal Representation:
Environmental Conditions:
QAPP Information: QA Info Missing
QAPP Information Reference(s):