Air Plan Approval; Pennsylvania; Redesignation of the Allegheny County Nonattainment Area to Attainment and Approval of the Area's Maintenance Plan for the 2010 1-Hour Primary Sulfur Dioxide National Ambient Air Quality Standard

The Environmental Protection Agency (EPA) is approving both a redesignation request and state implementation plan (SIP) revision submitted on November 14, 2023 by the Commonwealth of Pennsylvania on behalf of the Allegheny County Health Department (ACHD). The request asked the EPA to redesignate the Allegheny County, Pennsylvania area from nonattainment to attainment for the 2010 1-hour primary sulfur dioxide (SO<INF>2</INF>) national ambient air quality standard (NAAQS), while the revision included Allegheny County's maintenance plan for the 2010 1-hour primary SO<INF>2</INF> standard for the Allegheny County Area. The EPA is approving this redesignation of the Allegheny County Area from nonattainment to attainment for the 2010 SO<INF>2</INF> NAAQS and the revision to the Pennsylvania SIP in accordance with the requirements of the Clean Air Act (CAA).