Air Plan Approval; Pennsylvania; Allegheny County Area Fine Particulate Matter Clean Data Determination

The Environmental Protection Agency (EPA) is finalizing a determination that the Allegheny County, Pennsylvania nonattainment area has clean data for the 2012 annual fine particulate matter (PM<INF>2.5</INF>) national ambient air quality standard (NAAQS). This clean data determination (CDD) is based upon quality-assured, quality- controlled, and certified ambient air monitoring data showing the area has attained the 2012 annual PM<INF>2.5</INF> NAAQS based on the 2018- 2020 data available in EPA's Air Quality System (AQS) database. Based on this clean data determination, pursuant to EPA's Clean Data Policy, the obligation for Pennsylvania to make submissions to meet certain Clean Air Act (CAA or the Act) attainment plan requirements for the 2012 annual PM<INF>2.5</INF> NAAQS for the Allegheny County area is suspended for as long as the area continues to attain the 2012 annual PM<INF>2.5</INF> NAAQS. Following this final action, Pennsylvania's remaining obligation to submit contingency measures in response to EPA's May 14, 2021 conditional approval of Allegheny County's PM<INF>2.5</INF> attainment plan is suspended. Additionally, the federal implementation plan (FIP) clock, which was triggered by EPA's March 26, 2018 Finding of Failure to Submit an attainment plan for the 2012 PM<INF>2.5</INF> NAAQS for the Allegheny County Nonattainment Area, is suspended for the remaining contingency measures element conditionally approved as part of EPA's May 14, 2021 action on the Allegheny County PM<INF>2.5</INF> attainment plan.