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Application of Watershed Ecological Risk Assessment Methods to Watershed Management

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Information about this document as published in the Federal Register.

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Environmental Protection Agency (EPA).


Notice of availability.


EPA is announcing the availability of a final report titled, “Application of Watershed Ecological Risk Assessment Methods to Watershed Management” (EPA/600/R-06/037F), which was prepared by the National Center for Environmental Assessment (NCEA) within EPA's Office of Research and Development (ORD).


This document will be available on or about April 14, 2008.


The document will be available electronically through the NCEA Web site at​ncea. A limited number of paper copies will be available from the EPA's National Service Center for Environmental Publications (NSCEP), P.O. Box 42419, Cincinnati, OH 45242; telephone: 1-800-490-9198; facsimile: 301-604-3408; e-mail: Please provide your name, your mailing address, the title and the EPA number of the requested publication.

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The Information Management Team, National Center for Environmental Assessment (8601P), U.S. Environmental Protection Agency, 1200 Pennsylvania Avenue, NW., Washington, DC 20460. Telephone: 703-347-8561; fax: 703-347-8691; e-mail:

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Ecological risk assessment (ERA) is a process for analyzing environmental problems and is intended to increase the use of ecological science in decision making in order to evaluate the likelihood that adverse ecological effects may occur or are occurring as a result of exposure to one or more stressors. Applying ERA principles to watershed management makes scientific information more relevant to the needs of environmental managers. Watershed ERAs are complex because addressing impacts from multiple sources and stressors on multiple endpoints presents a scientific challenge and because multiple stakeholders have diverse interests. The needs of managers and stakeholders may change, and the need to take action may require using the best available information at the time, sometimes before an ERA is completed. Therefore, some flexibility of ERA methods is needed when performing watershed ERAs. It is also important that risk assessors and managers interact regularly and repeatedly.

This report supplements the Guidelines for Ecological Risk Assessment (U.S. EPA, 1998a) by addressing issues unique to ecological assessments of watersheds. Using lessons learned from watershed ERAs, the report presents guidance and examples for scientists performing watershed ecological assessments. The report also can be useful to risk assessors, watershed associations, landscape ecologists, and others seeking to increase the use of environmental assessment data in decision making.

Each activity and phase of the watershed ERA process is explained sequentially in this report. Guidance on how to involve stakeholders to generate environmental management goals and objectives is provided. The processes for selecting assessment endpoints, developing conceptual models, and selecting the exposure and effects pathways to be analyzed are described. Suggestions for predicting how multiple sources and stressors affect assessment endpoints are also provided; these include using multivariate analyses to compare land use with biotic measurements. In addition, the report suggests how to estimate, describe, and communicate risk and how to evaluate management alternatives.

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Dated: April 3, 2008.

Rebecca Clark,

Deputy Director, National Center for Environmental Assessment.

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[FR Doc. E8-7774 Filed 4-11-08; 8:45 am]