On June 6, EPA Administrator Pruitt sent a letter to governors to inform them of EPA’s efforts related to the National Ambient Air Quality Standards (NAAQS) for ozone promulgated in October 2015. EPA is extending the deadline for promulgating initial area designations, by one year, for the 2015 ozone NAAQS.
This news release is the full extent of information that EPA Regional offices have received on the subject.
https://www.epa.gov/newsreleases/epa-extend-deadline-2015-ozone-naaqs-area-designations