Aquatic Life Screening Value ALSV Methodology Assessment Proposed

US EPA is currently evaluating potential methods to derive “Aquatic Life Screening Value” ALSV, that could be used by EPA, States and Tribes to set water quality standards or used in ecological risk assessments. EPA has developed a set of draft white papers that explore: (1) the use of various tools to estimate aquatic toxicity data; (2) approaches for deriving community level benchmarks; and (3) procedures for better integrating plant effects data into community level assessments. A stakeholders meeting was held December 1, 2010, and the agency is accepting written comments on their proposed evaluation through January 15, 2011.

In order to characterize potential adverse effects of chemicals in the aquatic environment, the EPA, States an Tribes currently use available toxicity data from studies involving individual test species, which serve as surrogates for untested species. These data are collected for individual organisms exposed to chemicals and are then frequently extended to represent effects to populations of the same species, populations of similar genera/taxa, or to aquatic ecosystems. In many cases, the number of acceptable studies is very limited.

The goal of EPA’s current proposal is to examine how limited test results can best be used to characterize adverse effects on aquatic life, especially related to methods used by the Office of Pesticide Programs (OPP) and the Office of Water (OW). A portion of this work will address the derivation of an “Aquatic Life Screening Value” may be used to screen concentrations of pesticides and effluents in ambient waters. According to EPA, the ALSV might also be used by States and Tribes in the development of water quality standards.

EPA has proposed analyses to be conducted in order to determine the utility of specific methods to meet the mandates of the Clean Water Act (CWA) and the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). After the analysis of available tools and methods, the agency’s conceptual approach will be to refine and finalize specific methods and considerations for deriving ALSVs for chemicals.

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