Proposed rule · 2026-16083

Partial Approval and Partial Disapproval of Air Quality State Implementation Plans; Arizona; Prevention of Significant Deterioration Infrastructure Requirements for the 2012 Fine Particulate Matter National Ambient Air Quality Standard

The Environmental Protection Agency (EPA) is proposing to partially approve and partially disapprove a revision to the Arizona State implementation plan (SIP) as meeting the requirements of the Clean Air Act (CAA) for the implementation, maintenance, and enforcement of the 2012 fine particulate matter (PM<INF>2.5</INF>) national ambient air quality standard (NAAQS or "standards"). The EPA is proposing to approve the portions of Arizona's submission addressing prevention of significant deterioration (PSD) requirements in the permitting jurisdictions of the Arizona Department of Environmental Quality (ADEQ), Maricopa County Air Quality Department (MCAQD), and Pinal County Air Quality Control District (PCAQCD). The EPA is proposing to disapprove the portions of the Arizona submission addressing PSD requirements in the Pima County Department of Environmental Quality (PDEQ) permitting jurisdiction.