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

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name: Lion Creek (from confluence w San Antonio Creek to Resservoir)
Water Body ID: CAR4023101020110815101254
Water Body Type: River & Stream
Region 4     
Lion Creek (from confluence w San Antonio Creek to Resservoir)
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 Original
Impairment from Pollutant or Pollution: Pollutant
Regional Board Staff Conclusion: Benthic Community Effects is being considered for placement on the CWA section 303(d) List under sections 3.9 of the Listing Policy. Under section 3.9, an additional line of evidence associating the Benthic Community Effects with a water or sediment concentration of pollutants is necessary to assess listing status. [NUMBER] lines of evidence is/are available in the administrative record to assess this indicator. The sample had an IBI score above 40.

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 water 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.The sample had an IBI score above 40 but this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 2 samples is needed to determine impairment using Table 3.1.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

The CSCI is applicable statewide, accounts for a much wider range of natural variability, and provides equivalent scoring thresholds in all regions of the state. The CSCI will be used in the future for water quality assessment purposes statewide over the regional indices of biologic integrity (IBIs).
Regional Board Staff 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.
Line of Evidence (LOE) for Decision ID 66227, Benthic Community Effects
Region 4     
Lion Creek (from confluence w San Antonio Creek to Resservoir)
LOE ID: 85782
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: Not Recorded
Beneficial Use: Cold Freshwater Habitat
Number of Samples: 1
Number of Exceedances: 0
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: One sample was collected from Lion Canyon Creek in September 2006. The sample had an IBI score above 40. The score was 50.05 (2006).
Data Reference: Bioassessment Monitoring Report in Ventura River Watershed for, 2001-2007.
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 State or Regional Board. Region 4 Basin Plan.
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. For the Southern California IBI, sites with scores below 40 are considered to have impaired conditions.
Guideline Reference: Development of a Benthic Index of Biotic Integrity (B-IBI) for Wadeable Streams in Northern Coastal California and its Application to Regional 305(b) Assessment
Spatial Representation: The sample was collected at sites 7 Lion Canyon Creek upstream confluence of San Antonio Creek.
Temporal Representation: The sample was collected in September 2006.
Environmental Conditions:
QAPP Information: Sampling and laboratory procedures for this survey followed the California Stream Bioassessment Procedure (CSBP 2003) and also incorporated the Southern California Index of Biotic Integrity (IBI) (Ode et al., 2005).
QAPP Information Reference(s):