Limited Disapproval of Air Plan Revisions; Arizona; New Source Review; PM2.5

The Environmental Protection Agency (EPA) is finalizing a limited disapproval of a revision to the Arizona Department of Environmental Quality (ADEQ) portion of the Arizona State Implementation Plan (SIP) under the Clean Air Act (CAA or Act). This ADEQ-submitted SIP revision primarily was intended to serve as a replacement of ADEQ's SIP-approved rules for the issuance of New Source Review (NSR) permits for stationary sources, including but not limited to the rules governing the review and permitting of major sources and major modifications under the Act. This action concerns only the major nonattainment NSR provisions in ADEQ's submittal as they pertain to the Nogales and West Central Pinal nonattainment areas for particulate matter with a diameter of 2.5 micrometers or less (PM<INF>2.5</INF>). The EPA previously finalized a limited approval for these PM<INF>2.5</INF> nonattainment areas related to certain major nonattainment NSR permitting requirements for PM<INF>2.5</INF> under the CAA. We subsequently proposed a limited disapproval for these PM<INF>2.5</INF> nonattainment areas to set the stage for remedying certain deficiencies related to these nonattainment NSR permitting requirements for PM<INF>2.5</INF>, and this action finalizes this limited disapproval.