An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Environmental Measurements and Modeling

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

This guidance developed in 2009 provides recommendations for the effective development, evaluation, and use of models in environmental decision making once an environmental issue has been identified. These recommendations are drawn from Agency white papers, EPA Science Advisory Board reports, the National Research Council’s Models in Environmental Regulatory Decision Making, and peer-reviewed literature. 

You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.