Final rule · 2025-23259

Air Plan Approval: Arizona: Infrastructure Requirements for the 2012 Fine Particulate Matter National Ambient Air Quality Standard

The Environmental Protection Agency (EPA) is taking final action to approve portions of the state implementation plan (SIP) revisions submitted by the State of Arizona pursuant to 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 standards (NAAQS or "standards") as proposed, except for certain requirements related to prevention of significant deterioration (PSD), which EPA will defer action on until a later date. In addition, the EPA is approving regulatory provisions into the Arizona SIP and is amending regulatory text to include La Paz County as part of Mohave- Yuma Intrastate air quality control region (AQCR).