Air Plan Revisions; Arizona; Arizona Department of Environmental Quality; Gila County Reasonably Available Control Technology

The Environmental Protection Agency (EPA) is proposing to approve, under the Clean Air Act (CAA or "Act"), revisions to the Arizona state implementation plan (SIP) addressing reasonably available control technology (RACT) requirements for the 2015 ozone national ambient air quality standards (NAAQS or "standard") within the Gila County portion of the Phoenix-Mesa ozone nonattainment area. This proposal explains our evaluation of Arizona's SIP submittal and basis for proposing approval.