An official website of the United States government.

We've made some changes to If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Ozone Designations

2015 Ozone Standards - EPA Intended Area Desigantions for Other Tribes

The letters below summarize EPA's intended designations for tribes that did not submit recommendations to EPA but may be potentially impacted by a nonattainment designation in the surrounding area, and for tribes with Treatment as a State status for Clean Air Act section 107(d).  

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