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 www.epa.gov. 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 This website is no longer updated and links to external websites and some internal pages may not work.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 »

Clean Air Markets

Air Quality Modeling Technical Support Document for the 2008 Ozone NAAQS Cross-State Air Pollution Rule Proposal

This document describes the air quality modeling performed for the proposed rule including the components and evaluation of the 2011-based modeling platform, the determination of 2017 nonattainment and maintenance receptors, the calculation of 2017 ozone contributions, the evaluation of contributions using the 1 percent of the NAAQS threshold, and the identification of upwind state-to-downwind receptor linkages.

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