Proposed rule · 2025-20409

Air Plan Approval; Pennsylvania; Redesignation Request for the Allegheny County Area for the 2012 Annual Fine Particulate Matter Standard

The Environmental Protection Agency (EPA) is proposing to approve a request from the Commonwealth of Pennsylvania to redesignate the Allegheny County, Pennsylvania nonattainment area (Allegheny County Area) to attainment for the 2012 annual fine particulate matter (PM<INF>2.5</INF>) national ambient air quality standard (NAAQS or standard). The EPA has already approved, as a revision to the Pennsylvania state implementation plan (SIP), a maintenance plan that demonstrates maintenance of the 2012 annual PM<INF>2.5</INF> NAAQS through 2035 in the Allegheny County Area. The redesignation request was submitted by the Commonwealth of Pennsylvania Department of Environmental Protection (PADEP or Pennsylvania) on behalf of the Allegheny County Health Department (ACHD). This action is being taken under the Clean Air Act (CAA).