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

Ozone Designations Regulatory Actions

This page contains a chronological listing of all regulatory actions related to designations for the 2015 ozone standards.

October 4, 2018 - EPA corrected errors in the regulatory text regarding the designation of certain areas for the 2015 ozone standards.  Learn more

July 17, 2018 - EPA completed designations for the San Antonio, Texas metropolitan area. Learn more

April 30, 2018 - EPA completed additional area designations for the 2015 ozone standards. Learn more

March 19, 2018 - EPA responds to Texas recommendations for the San Antonio Area. Learn more

December 22, 2017 - EPA responds to state and tribal recommendations by indicating the anticipated area designations for most remaining portions of the U.S.  Learn more

November 6, 2017 – Consistent with the states’ and tribes’ recommendations, EPA designates most of the U.S. “attainment/unclassifiable” for the 2015 ozone standards. Learn more

August 2, 2017 -Withdrawal of Extension of Deadline for Promulgating Designations for the 2015 Ozone National Ambient Air Quality Standards.  Read the Withdrawal of Extension Notice.

June 6, 2017 - The Administrator has determined that there is insufficient information to complete area designations for the 2015 ozone standards and is extending the deadline by one year, until October 1, 2018. Learn more

State representatives and some tribal representatives have submitted area designation recommendations for the 2015 ozone standards.