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 This website is no longer updated and links to external websites and some internal pages may not work.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

Impaired Waters and TMDLs

FY2010 National Report on Implementing TMDLs

The national study analyzed the frequency of TMDL implementation through NPDES permits and Section 319 projects and discusses how data gaps influence assessment results.

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