Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Adoption of the Liberty-Clairton Nonattainment Area 1997 Fine Particulate Matter National Ambient Air Quality Standard Attainment Demonstration

Riepilogo

EPA is proposing to approve, with one condition, State Implementation Plan (SIP) revisions submitted by the Pennsylvania Department of Environmental Protection (PADEP) on June 17, 2011. These revisions include the 1997 fine particulate matter (PM 2.5 ) National Ambient Air Quality Standard (NAAQS) attainment plan for the Liberty-Clairton nonattainment area (Liberty-Clairton Area) including a request for EPA to make a determination that the appropriate attainment deadline for this nonattainment area is April 5, 2015. EPA is proposing to approve the attainment plan for the Liberty-Clairton Area that includes the emissions inventories, the reasonably available control measures/reasonably available control technology (RACM/RACT), reasonable further progress (RFP), and contingency measures portions of the attainment demonstration, and the transportation conformity motor vehicle emissions budgets (MVEBs) that demonstrate attainment of the 1997 PM 2.5 NAAQS. EPA is proposing to conditionally approve the air quality modeling submitted to demonstrate attainment of the 1997 PM 2.5 NAAQS. In order for EPA to fully approve the modeling analysis, PADEP must update the modeling to ensure that th