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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, 2025. This website is no longer updated and links to external websites and some internal pages may not work. More information »

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Great Lakes Areas of Concern

  • Great Lakes Restoration Initiative Action Plan IV

    The U.S. Environmental Protection Agency announces an updated action plan for federal agencies and their partners under the Great Lakes Restoration Initiative to restore and protect the Great Lakes over the next five years.

  • 2025 Great Lakes Areas of Concern Conference in Toledo, Ohio

    Save the date! The Great Lakes AOC Conference will be held September 16-18, 2025, in Toledo, Ohio.

    More information to come. 

The U.S.-Canada Great Lakes Water Quality Agreement (Annex 1 of the 2012 Protocol) defines AOCs as "geographic areas designated by the Parties where significant impairment of beneficial uses has occurred as a result of human activities at the local level." An AOC is a location that has experienced environmental degradation. EPA and other federal and state agencies are working to restore the 25 remaining U.S. AOCs in the Great Lakes basin.

AOC Map

Map of the US great lakes areas of concern

    AOC List, Map and Contacts

    Projects and Progress

    photo of an aoc with water and native plants
    • Restoring Great Lakes Areas of Concern
    • Beneficial Use Impairments
    • Remedial Action Plans
    • Legacy Act

    Delisted AOCs

    United States:
    • Rochester Embayment (Oct. 2024)
    • Ashtabula River (Aug. 2021)
    • Lower Menominee (Aug. 2020)
    • White Lake (Oct. 2014)
    • Deer Lake (Oct. 2014)
    • Presque Isle Bay (Feb. 2013)
    • Oswego River (July 2006)
    Canada:
    • Collingwood Harbour
    • Severn Sound
    • Wheatley Harbour

    Related Information

    • Environment and Climate Change Canada: Great Lakes AOCs
    • Great Lakes Commission AOC Resources 
    • International Joint Commission
    Contact Us About Great Lakes AOCs to ask a question, provide feedback, or report a problem.
    Last updated on December 3, 2024
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