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Air Quality Designations for Ozone

  • Remand Response

    The Clean Air Act requires EPA to designate areas in the United States after the agency sets a new National Ambient Air Quality Standard (NAAQS) or revises an existing standard

    November 17, 2021 - EPA completes response to remand issued by the DC Circuit Court on certain area designations for the 2015 ozone standards. 

This web site provides information on the process EPA, the states, and the tribes follow to designate areas as "attainment" (meeting) or "nonattainment" (not meeting) the ground-level ozone standards EPA strengthened in 2015.

Learn About Ozone Designations

  • Ozone designations process
  • Basis for air quality designations

Regulatory Actions and Guidance for the 2015 Ozone Designations

  • Regulatory actions
  • Designations guidance and data

Where You Live

  • State designations
  • Tribal designations
  • Learn about your local ozone levels

Related Information

  • Basic information on ozone pollution
  • Scientific and technical information related to the ozone NAAQS
  • Previous ozone designations
  • Implementing ozone standards
  • Other pollutant designations
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on May 13, 2025
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