Draft 2008 California 303(d)/305(b) Integrated Report

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name: Compton Creek
Water Body ID: CAR4051501019990202111430
Water Body Type: River & Stream
 
DECISION ID
16468
 
Pollutant: Toxicity
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
 
Weight of Evidence: This pollutant is being considered for placement on the section 303(d) list under section 3.6 of the Listing Policy. Under section 3.6 a one line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of the samples exceed the water quality objective.

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. Zero of one samples exhibited significant toxicity to Pimephales promelas and Ceriodaphnia dubia and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of two samples is needed for application of 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.
 
RWQCB Board Decision / Staff 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 because applicable water quality standards are not being exceeded.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 16468
 
LOE ID: 28251
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Wildlife Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Zero out of one samples exhibited significant acute and chronic toxicity to Pimephales promelas and Ceriodaphnia dubia. Water quality samples for toxicity were taken in compliance with the Surface Water Ambient Monitoring Program's monitoring and testing parameters.
Data Reference: Surface Water Ambient Monitoring Program data for all watersheds in the Los Angeles Region 2001-2005.
 
Water Quality Objective/Criterion: The Basin Plan states at there shall be no acute or chronic toxicity in ambient waters outside mixing zones.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
  Basin Plan Amendments to the Water Quality Control Plan Los Angeles Region R4 Basin Plan as of 02/02/2009
 
Evaluation Guideline: Toxicity was defined as a statistically significant effect in the sample exposure compared to the control using EPA recommended hypothesis testing (parametric Dunnett's Test or non-parametric Fisher's Exact Test).
Guideline Reference: Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to freshwater and Marine Organisms. Fourth Edition. EPA/600/4-90/027F. August 1993. Washington DC
 
Spatial Representation: Water toxicity monitoring was conducted in Compton Creek at station 412LARCMP (Lat: 33.84644, Long: -118.20883).
Temporal Representation: A grab sample was taken on 06/30/2005.
Environmental Conditions:
QAPP Information: Data was collected in compliance with the sampling and monitoring procedures detailed in the Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)