Final rule · 2025-13893

Air Plan Approval; Pennsylvania; Redesignation Request and Associated Maintenance Plan for the Liberty-Clairton Area for the 1997 Annual and 2006 24-Hour Fine Particulate Matter Standard and Maintenance Plan for the Allegheny County Area for the 2012 Annual Fine Particulate Matter Standard

The Environmental Protection Agency (EPA) is approving the Commonwealth of Pennsylvania's request to redesignate to attainment the Liberty-Clairton, Pennsylvania nonattainment area (Liberty-Clairton Area) for the 1997 annual and 2006 24-hour fine particulate matter (PM<INF>2.5</INF>) national ambient air quality standards (NAAQS or standard). The EPA has determined that the Liberty-Clairton Area attained both the 1997 annual and 2006 24-hour PM<INF>2.5</INF> NAAQS and has met the statutory requirements for redesignation. The EPA is approving, as a revision to the Pennsylvania State Implementation Plan (SIP), the Commonwealth's plan for maintaining the 1997 annual and 2006 24-hour PM<INF>2.5</INF> NAAQS through 2035 for the Liberty-Clairton Area. Additionally, the EPA is approving the maintenance plan for the Allegheny County, Pennsylvania nonattainment area (Allegheny County Area) for the 2012 annual PM<INF>2.5</INF> NAAQS through 2035. The maintenance plan includes 2017, 2026, and 2035 mobile vehicle emissions budgets (MVEBs) for mobile sources of PM<INF>2.5</INF> and nitrogen oxides (NO<INF>X</INF>) for the Allegheny County Area for the 2012 annual PM<INF>2.5</INF> NAAQS, which the EPA is approving for transportation conformity purposes. This action does not redesignate the Allegheny County Area to attainment for the 2012 annual PM<INF>2.5</INF> NAAQS. Both the redesignation request and maintenance plan were 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 CAA.