Draft California 2014 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name: Triunfo Canyon Creek Reach 2
Water Body ID: CAR4042400019990202082235
Water Body Type: River & Stream
 
DECISION ID
43610
Region 4     
Triunfo Canyon Creek Reach 2
 
Pollutant: Benthic Community Effects
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)(2012)
Revision Status Original
Sources: Source Unknown
Expected TMDL Completion Date: 2021
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff Conclusion: This pollutant is being considered for the section 303(d) list under section 3.9 of the Listing Policy. Under section 3.9, waters are listed when a bioassessment shows diminished numbers of species or other metrics (compared to a reference site) and it is associated with another pollutant.

One line of evidence is available in the administrative record to assess this pollutant. Benthic macroinvertebrates as measured by Southern California IBI (index of biological integrity) in Triunfo Creek Reach 2 were very poor in the spring and very poor in the fall of 2005. indicating impairment of benthic community structure.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification to place the water segment in category 4C on 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. There is at least one bioassessment sample (Index of Biological Integrity score) to satisfy Section 3.9
4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.



State Board Review and Conclusion:
State Water Board staff used a situation-specific weight of evidence approach to evaluate the Los Angeles Water Board benthic macroinvertebrate ?bioassessment listing. State Water Board staff determined that it is necessary to include these listings because additional data analyses and multiple line of evidence show that benthic macroinvertebrate populations are impacted by a wide range of stressors. Using this approach staff followed a three-step process for evaluation of all available water quality data including the chemistry and bioassessment data. In the first step, staff reviewed the Los Angeles Water Board data evaluation for bioassessment listing. In the second step, staff reviewed all other available bioassessment data because State Water Board staff learned that some data had not been considered for this listing decision by the Regional Water Board. In step 3 staff reviewed the chemistry water quality data available for lead, mercury, sedimentation/siltation, total nitrogen, and total phosphorus to determine the water quality condition in this water body segment.

In step 1 and 2, State Water Board staff evaluated the bioassessment data using the Southern California index of biological integrity (IBI). Staff reviewed the line of evidence prepared by the Los Angeles Water Board and additional bioassessment data. Benthic macroinvertebrate as measured by Southern California IBI in Triunfo Creek was sampled, below Westlake were poor in 2005 indicating impairment of benthic community structure.

In step 3, the chemistry data for lead, mercury, sedimentation/siltation, total nitrogen, and total phosphorus were evaluated by State Water Board staff. Data for lead, mercury, and sedimentation/siltation were evaluated in a previous listing cycle. Lead, mercury, and sedimentation/siltation showed impairment to the warm freshwater habitat and it resulted in listing this water body in 1996 and 2002. In this step State Water Board staff evaluated the most recent available data for total nitrogen and total phosphorus. The data for total nitrogen show that one of six samples exceeded the TMDL target of 1.0 mg/L for total nitrogen during the summer. The data for total phosphorus show that one of six samples exceeded the TMDL target of 0.1mg/L for total phosphorus during the summer. The weight of evidence of the data and information indicate that the beneficial use of the water is not supported.

The water quality chemistry and bioassessment data provide a substantial basis that benthic macroinvertebrate populations are impacted by a wide range of anthropogenic stressors. Based on the available data and information, staff recommend to list for benthic macroinvertebrate-bioassessment.
 
Regional Board Staff 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 cycle. The decision has not changed.
 
 
Line of Evidence (LOE) for Decision ID 43610, Benthic Community Effects
Region 4     
Triunfo Canyon Creek Reach 2
 
LOE ID: 30527
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Wildlife Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: The IBI scores at this site ranked in the ?very poor? range (13) in the spring and ?very poor? (3) in the fall.
Data Reference: Malibu Watershed 2005 Bioassessment Monitoring Report. (2005) The Malibu Creek Watershed Monitoring Program City of Calabasas, Environmental Services Division. Submitted by: Aquatic Bioassay and Consulting Laboratories.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Basin Plan states that: "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 State or Regional Board.?
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The IBI is a multi-metric assessment that employs biological metrics that respond to a habitat or water quality impairment. Each of the biological metrics measured at a site are converted to an IBI score then summed. These cumulative scores are then ranked as very good (80-100), good (60-79), fair (40-49), poor (20-39) and very poor (0-19) habitat conditions. Sites with scores below 39 are considered to have impaired conditions.
Guideline Reference: A Quantitative Tool for Assessing the Integrity of Southern Coastal California Streams. Appendix 7-B Environmental Management Vol. 35, No. 4, pp. 493-504.
 
Spatial Representation: One site in Triunfo Creek was sampled, below Westlake at 34 07.927' N 118 49.237' W
Temporal Representation: Sites were sampled in Spring and Fall of 2005
Environmental Conditions: Benthic macroinvertebrate populations and IBI scores may also be affected by a wide range of anthropogenic stressors.
QAPP Information: Data was collected in compliance with California Stream Bioassessment Procedure.
QAPP Information Reference(s): California Stream Bioassessment Procedure (Protocol Brief for Biological and Physical/Habitat Assessment in Wadeable Streams) California Department of Fish and Game Water Pollution Control Laboratory Aquatic Bioassessment Laboratory Revision Date - December, 2003
 
 
DECISION ID
36162
Region 4     
Triunfo Canyon Creek Reach 2
 
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)(2012)
Revision Status Original
Sources: Source Unknown
Expected TMDL Completion Date: 2019
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 Staff 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 cycle. The decision has not changed.
 
 
Line of Evidence (LOE) for Decision ID 36162, Lead
Region 4     
Triunfo Canyon Creek Reach 2
 
LOE ID: 4252
 
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):
 
 
DECISION ID
35242
Region 4     
Triunfo Canyon Creek Reach 2
 
Pollutant: Mercury
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)(2012)
Revision Status Original
Sources: Source Unknown
Expected TMDL Completion Date: 2019
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 Staff 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 cycle. The decision has not changed.
 
 
Line of Evidence (LOE) for Decision ID 35242, Mercury
Region 4     
Triunfo Canyon Creek Reach 2
 
LOE ID: 4253
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Not Recorded
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
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
35060
Region 4     
Triunfo Canyon Creek Reach 2
 
Pollutant: Sedimentation/Siltation
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)(2012)
Revision Status Original
Sources: Source Unknown
Expected TMDL Completion Date: 2019
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Staff 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 Staff 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 cycle. The decision has not changed.
 
 
Line of Evidence (LOE) for Decision ID 35060, Sedimentation/Siltation
Region 4     
Triunfo Canyon Creek Reach 2
 
LOE ID: 4254
 
Pollutant: Sedimentation/Siltation
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):