What are the revised draft atrazine criteria concentrations?
Freshwater Aquatic Life: Except possibly where a locally important species is very sensitive, freshwater aquatic life and their uses should not be affected unacceptably if the one-hour average concentration of atrazine does not exceed 1,500 µg/L more than once every three years on the average (acute criterion) and if the Average Primary Producer Steinhaus Similarity deviation for a site is less than 5% (as determined using Comprehensive Aquatic Systems Model (CASM) or other appropriate model and index) and is not exceeded more than once every three years (or other appropriate return frequency sufficient to allow system recovery). The 5% index for the protection of aquatic plant community should also be protective of most freshwater animals (chronic criterion). Saltwater Aquatic Life: Except possibly where a locally important species is very sensitive, saltwater aquatic life and their uses should not be affected unacceptably if the one-hour average concentration of atrazine does not exc
