Air Plan Approval; Arizona; Stationary Sources; New Source Review

The Environmental Protection Agency (EPA) is taking final action to approve revisions to the Arizona Department of Environmental Quality (ADEQ) portion of the applicable Clean Air Act (CAA or Act) state implementation plan (SIP) for the State of Arizona (State). We are approving revisions that are primarily intended to correct deficiencies in ADEQ's SIP-approved rules for the issuance of New Source Review (NSR) permits for stationary sources, with a focus on the Act's preconstruction permit requirements for major sources and major modifications. This action also finalizes a conditional approval of ADEQ's NSR program with respect to the CAA requirements related to ammonia as a precursor to fine particulate matter (PM2.5) under the nonattainment NSR (NA-NSR) program requirements in CAA section 189(e). In addition, this action permanently terminates the sanctions clock associated with deficiencies being corrected by the rules being approved today, except that this action continues the deferral of sanctions under the Act related to PM2.5 precursors under section 189(e) of the Act for the NA-NSR program.