Final California 2010 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name: Wilmington Drain
Water Body ID: CAR4051200020020307110435
Water Body Type: River & Stream
 
DECISION ID
7114
Region 4     
Wilmington Drain
 
Pollutant: Ammonia
Final Listing Decision: Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2006)
Revision Status Revised
Reason for Delisting: Applicable WQS attained; reason for recovery unspecified
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for removal from the section 303(d) list under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status.

Two line of evidence is available in the administrative record to assess this pollutant.
Line of evidence (LOE) 4278 will not be considered for this decision because it is a placeholder LOE. The original data was not able to be assessed using current standards due to lack of temperature and pH data. The recent data listed in LOE 27904 provides a sufficient assessment of conditions in the water body.


Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for removing this water segment-pollutant combination from the 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 29 samples exceeded the the 30-day average objective for ammonia and this does not exceed the allowable frequency listed in Table 4.1 of the Listing Policy.
4. Pursuant to section 4.11 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 removed from the section 303(d) list because applicable water quality standards for the pollutant are not 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.
 
USEPA Action (if applicable):
 
 
Line of Evidence (LOE) for Decision ID 7114, Ammonia
Region 4     
Wilmington Drain
 
LOE ID: 27904
 
Pollutant: Ammonia
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Preservation of Rare & Endangered Species | Wetland Habitat | Wildlife Habitat
 
Number of Samples: 29
Number of Exceedances: 1
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: One of 29 samples exceeded the 30-day average objective for ammonia. The sample value for the exceedance was 0.63 mg/L and the 30 day average objective based on temperature and pH was 0.44 mg/L.

The pH data used ranged from 7.5 - 9.0. The temperature data used ranged from 9.0 - 23.0 C. There were 29 pH and temperature data points corresponding to 29 ammonia samples analyzed.

Water quality samples were taken and analyzed for ammonia in as part of the City of Los Angeles Watershed Protection Division's Machado Lake Nutrients Monitoring Program.
Data Reference: Water quality monitoring for Wilmington Drain at Lomita Blvd.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Basin Plan states, "In order to protect aquatic life, ammonia concentrations in inland surface waters characteristic of freshwater shall not exceed the values calculated for the appropriate instream conditions shown in Tables 3-1 to 3-3." The one-hour average objective is dependent on pH and the presence or absence of early life stages of fish (ELS) but not temperature. The 30-day average objective is dependent on pH, temperature and ELS in Tables 3-1 to 3-3. The ammonia objectives and the pH and temperature dependent formula are found in Attachment A of Regional Board Resolution No. 2002-011.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The City of Los Angeles Watershed Protection Division conducted sampling in Wilmington Drain at the water quality monitoring station near Lomita Boulevard.
Temporal Representation: Grab samples were taken and analyzed on a biweekly basis from October 2007 to June 2008.
Environmental Conditions:
QAPP Information: Data was collected in accordance with the City of Los Angeles Pollution Assessment Section's Standard Operating Procedures for monitoring and testing.
QAPP Information Reference(s): Quality Assurance Manual Prepared for The Analysts, Supervisors, and Managers of the Environmental Monitoring Division, Bureau of Sanitation, Department of Public Works, City of Los Angeles
 
Line of Evidence (LOE) for Decision ID 7114, Ammonia
Region 4     
Wilmington Drain
 
LOE ID: 4278
 
Pollutant: Ammonia
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 pre-2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Unspecified
Objective/Criterion Reference: Placeholder reference pre-2006 303(d)
 
Evaluation Guideline: Unspecified
Guideline Reference: Placeholder reference pre-2006 303(d)
 
Spatial Representation: Unspecified
Temporal Representation: Unspecified
Environmental Conditions: Unspecified
QAPP Information: Unspecified
QAPP Information Reference(s):
 
 
DECISION ID
7205
Region 4     
Wilmington Drain
 
Pollutant: Coliform Bacteria
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2006)
Revision Status Original
Sources: Nonpoint Source
Expected TMDL Completion Date: 2007
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed.
 
Regional Board Decision Recommendation: 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.
 
USEPA Action (if applicable): USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant.
 
 
Line of Evidence (LOE) for Decision ID 7205, Coliform Bacteria
Region 4     
Wilmington Drain
 
LOE ID: 4279
 
Pollutant: Coliform Bacteria
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Water Contact Recreation
 
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 pre-2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Unspecified
Objective/Criterion Reference: Placeholder reference pre-2006 303(d)
 
Evaluation Guideline: Unspecified
Guideline Reference: Placeholder reference pre-2006 303(d)
 
Spatial Representation: Unspecified
Temporal Representation: Unspecified
Environmental Conditions: Unspecified
QAPP Information: Unspecified
QAPP Information Reference(s):
 
 
DECISION ID
7232
Region 4     
Wilmington Drain
 
Pollutant: Copper
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2006)
Revision Status Original
Sources: Nonpoint Source
Expected TMDL Completion Date: 2019
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed.
 
Regional Board Decision Recommendation: 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.
 
USEPA Action (if applicable): USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant.
 
 
Line of Evidence (LOE) for Decision ID 7232, Copper
Region 4     
Wilmington Drain
 
LOE ID: 4280
 
Pollutant: Copper
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 pre-2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Unspecified
Objective/Criterion Reference: Placeholder reference pre-2006 303(d)
 
Evaluation Guideline: Unspecified
Guideline Reference: Placeholder reference pre-2006 303(d)
 
Spatial Representation: Unspecified
Temporal Representation: Unspecified
Environmental Conditions: Unspecified
QAPP Information: Unspecified
QAPP Information Reference(s):
 
 
DECISION ID
7234
Region 4     
Wilmington Drain
 
Pollutant: Lead
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2006)
Revision Status Original
Sources: Nonpoint Source
Expected TMDL Completion Date: 2019
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed.
 
Regional Board Decision Recommendation: 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.
 
USEPA Action (if applicable): USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant.
 
 
Line of Evidence (LOE) for Decision ID 7234, Lead
Region 4     
Wilmington Drain
 
LOE ID: 4281
 
Pollutant: Lead
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 pre-2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Unspecified
Objective/Criterion Reference: Placeholder reference pre-2006 303(d)
 
Evaluation Guideline: Unspecified
Guideline Reference: Placeholder reference pre-2006 303(d)
 
Spatial Representation: Unspecified
Temporal Representation: Unspecified
Environmental Conditions: Unspecified
QAPP Information: Unspecified
QAPP Information Reference(s):