Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Redesignation Request and Associated Maintenance Plan for the Pennsylvania Portion of the Philadelphia-Wilmington, PA-NJ-DE Nonattainment Area for the 1997 Annual and 2006 24-Hour Fine Particulate Matter Standard

The Environmental Protection Agency (EPA) is approving the Commonwealth of Pennsylvania's request to redesignate to attainment the Pennsylvania portion of the Philadelphia-Wilmington, PA-NJ-DE Nonattainment Area (Philadelphia Area or Area) for the 1997 annual and 2006 24-hour fine particulate matter (PM<INF>2.5</INF>) national ambient air quality standard (NAAQS or standard). EPA has determined that the Philadelphia Area attained both the 1997 annual and 2006 24- hour PM<INF>2.5</INF> NAAQS. In addition, EPA is approving as a revision to the Pennsylvania State Implementation Plan (SIP) the associated maintenance plan to show maintenance of the 1997 annual and 2006 24-hour PM<INF>2.5</INF> NAAQS through 2025 for the Pennsylvania portion of the Area. The maintenance plan includes the 2017 and 2025 PM<INF>2.5</INF> and nitrogen oxides (NO<INF>X</INF>) mobile vehicle emissions budgets (MVEBs) for the Pennsylvania portion of the Area for the 1997 annual and 2006 24-hour PM<INF>2.5</INF> NAAQS, which EPA is approving for transportation conformity purposes. Furthermore, EPA is approving the 2007 base year emissions inventory included in the maintenance plan for the Pennsylvania portion of the Area for the 2006 24-hour PM<INF>2.5</INF> NAAQS. These actions are being taken under the Clean Air Act (CAA).