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 This website is no longer updated and links to external websites and some internal pages may not work.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

Great Lakes AOCs

Progress in the AOCs

Areas of Concern are designated by the International Joint Commission as geographic areas in the Great Lakes basin having severe environmental degredation. There are 43 Areas of Concern with 26 in the United States, 17 in Canada, and five shared by the two countries.

These maps show the location and status of the U.S. AOCs. 

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