Contract no. 68-01-6403. "Prepared for U.S. Environmental Protection Agency, Office of Water Regulations and Standards, Criteria and Standards Division."

In an effort to assist the states in adapting the National water quality criteria to local conditions, EPA has proposed a series of protocols for consideration. One of the protocols, referred to as the State Resident Species Recalculation, modifies the National water quality criteria to reflect the state resident species composition. With the protocol, state water quality criteria may be calculated without the need for additional toxicity testing. The state Resident Species Recalculation Protocol is implemented in this report. The report includes: a survey of the published literature on the geographical distributions in the United States of 95 freshwater species in the national data base; and a recalculation of state water quality criteria for 21 toxic chemicals whose national water quality criteria have been published by EPA. Only five percent of the 21 chemicals have met the minimum data requirements on the national level. The state data base is used to recalculate the maximum water quality criteria even when all of the data requirements are not satisfied. Sixty-five percent of these have state criteria which are more stringent than the national criteria. The recalculated instantaneous maximum criteria have been obtained by extrapolation for all cases but two (copper criteria for Maine and New York). The validity of the state water quality criteria is largely dependent on the correct representation of the sensitivity of the state resident population by the resident species data base. Within the framework of the current guidelines and the resident species recalculation method, the results of this study may always be modified with additional toxicity data.