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Risk Assessment

Freshwater Screening Benchmarks

Hierarchy for Selection of Freshwater Benchmarks

  • Preference was given to the benchmarks based on chronic exposure, non-lethal endpoint studies designed to be protective of sensitive species.
  • Absent chronic exposure benchmarks, values based on acute studies for multiple species adjusted with acute to chronic ratios were selected.
  • Food chain values for water from the EPA Great Lakes Water Quality Initiative were included based on the extent of benchmark evaluation process and the approval of models for DDT, mercury, 2,3,7,8-TCDD, and PCBs.
  • Other food chain values were given preference over direct toxicity values only if the direct toxicity value was for a marine environment.

Author: Bruce Pluta (Region 3)
Date: July 2006
Description: Screening benchmarks for freshwater in Region 3
Keywords: freshwater, screening benchmarks, risk assessment, Superfund, Region 3, water, ERAGS, SLERA


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