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Guidance on the Development, Evaluation, and Application of Environmental Models

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Environmental Protection Agency (EPA).


Notice of Document Availability.


The U.S. Environmental Protection Agency (EPA) is announcing the availability of the final “Guidance Document on the Development, Evaluation, and Application of Regulatory Environmental Models,” EPA/100/K-09/003 (hereinafter “Models Guidance”). EPA's Council for Regulatory Environmental Modeling (CREM) developed the Models Guidance and its companion product, the “Models Knowledge Base” (hereinafter “Models KBase,”​crem/​knowledge_​base/​knowbase.cfm), to Start Printed Page 14552improve the practices associated with the development, evaluation, and application of models for environmental decision making. Furthermore, by providing access to its tools and methods, EPA increases transparency and can improve the public's understanding of how science is used to make environmental decisions.

While the Models Guidance does not impose legally binding requirements on EPA or the public, it provides recommendations on the principles of good modeling practice, stressing the importance of model quality, documentation, and transparency with the aim of helping to determine when and how a model can be used to inform a decision.


The Models Guidance is available electronically through the CREM Web site:​crem. A limited number of paper copies will be available from EPA's National Service Center for Environmental Publications (NSCEP), P.O. Box 42419, Cincinnati, OH 45242; telephone 1-800-490-9198 or 513-489-8190; facsimile: 301-604-3408; e-mail: Please provide your name, mailing address, title, and EPA number (as given above) of the requested publication.

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Dr. Noha Gaber, Council for Regulatory Environmental Modeling, Office of the Science Advisor, 1200 Pennsylvania Ave, NW., Mail Code: 8105R, Washington, DC 20460; by telephone/voice mail at 202-564-2179; Fax: 202-564-2070; or via e-mail at

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To achieve its mission of protecting human health and safeguarding the natural environment, the U.S. Environmental Protection Agency (EPA) often employs mathematical models to study environmental systems and processes. These modeling analyses often provide input for the development of regulatory decisions. EPA established the Council for Regulatory Environmental Modeling (CREM) in 2000 in an effort to improve the quality, consistency and transparency of EPA models. In 2003, the EPA Administrator directed the CREM to provide guidance for the development, assessment, and use of environmental models and to develop a publicly-accessible inventory of EPA's most frequently used models. The Models Guidance and Models KBase were developed in close collaboration with members of the CREM, who represent EPA's program and regional offices. This document represents the consensus view among EPA offices. The Models Guidance was also evaluated and approved by the EPA's Science Policy Council, the Agency's forum for senior level policy deliberation and coordination on significant science issues.

Both the Models Guidance and the Models KBase were issued in draft form in January 2004. In addition to internal review, the CREM products have undergone an external review process through EPA's Science Advisory Board (the report may be found at​sab/​panels/​cremgacpanel.html). The CREM also commissioned the National Academy of Science's (NAS) National Research Council to assess evolving scientific and technical issues related to the selection and use of computational and statistical models in decision making processes at EPA. The NRC report, entitled “Models of Environmental Regulatory Decision Making,” was released in 2007 and provides advice on the management, evaluation, and use of models at the EPA. The report may be found at​catalog.php?​record_​id=​11972.

A revised draft of the Models Guidance, which built on the recommendations of the Science Advisory Board review panel and the NRC report, was issued for public comment in August 2008.

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Dated: March 5, 2009.

Kevin Teichman,

Acting EPA Science Advisor.

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[FR Doc. E9-7183 Filed 3-30-09; 8:45 am]