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Invited Expert Meeting on Revising U.S. EPA's Guidelines for Deriving Aquatic Life Criteria

On September 14-16, 2015, EPA, Office of Water, Office of Science and Technology, hosted an invited expert meeting to gather information regarding the state of the science for ecological risk assessment as it pertains to revising the 1985 Guidelines (Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses, Stephan et al. 1985). These Guidelines are used as the basis for deriving National Ambient Water Quality Criteria for the protection of aquatic life. This meeting garnered input from technical experts on aspects of ecological risk assessment and criteria derivation and provided an opportunity for a public comment period.

EPA is considering information presented during the meeting regarding new and alternative methods for deriving aquatic life criteria in our effort to update the 1985 Guidelines.

The agenda for the meeting and PowerPoint presentations from the invited experts are presented below.

For further information, contact Mike Elias (

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