Revisions to Air Plan; Arizona; Stationary Sources; New Source Review

The Environmental Protection Agency (EPA) is proposing a limited approval and limited disapproval of revisions to the Arizona Department of Environmental Quality (ADEQ) portion of the applicable state implementation plan (SIP) for the State of Arizona. These revisions are primarily intended to serve as a replacement of ADEQ's existing SIP-approved rules for the issuance of New Source Review (NSR) permits for stationary sources, including but not limited to review and permitting of major sources and major modifications under the Clean Air Act (CAA or Act). After a lengthy stakeholder process, the State of Arizona developed and submitted a NSR program for SIP approval that satisfies most of the applicable Clean Air Act and NSR regulatory requirements, and will significantly update ADEQ's existing SIP- approved NSR program. It also represents an overall strengthening of ADEQ's SIP-approved NSR program by clarifying and enhancing the NSR permitting requirements for major and minor stationary sources. This proposed action will update the applicable plan and set the stage for remedying certain deficiencies in these rules. We are seeking comment on our proposed action and plan to follow with a final action.