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

The Environmental Protection Agency (EPA) is finalizing a limited approval and limited disapproval of, and other actions on, revisions to the Arizona Department of Environmental Quality (ADEQ) portion of the applicable state implementation plan (SIP) for the State of Arizona (State or Arizona) under the Clean Air Act (CAA or Act). These revisions submitted by Arizona 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 review and permitting of major and minor sources under the Act. After a lengthy stakeholder process, the State submitted a NSR program for SIP approval that satisfies most of the applicable CAA and NSR regulatory requirements, and which 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 requirements for major and minor stationary sources. This final action updates the applicable plan while allowing ADEQ to remedy certain deficiencies in ADEQ's rules.