Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Determinations of Attainment of the 1997 Annual Fine Particulate Standards for the Liberty-Clairton Nonattainment Area

EPA is making two separate and independent determinations regarding the Liberty-Clairton, Pennsylvania 1997 annual fine particulate (PM<INF>2.5</INF>) nonattainment area (the Liberty-Clairton Area). First, EPA is determining that the Liberty-Clairton Area attained the 1997 PM<INF>2.5</INF> annual national ambient air quality standards (NAAQS) by the applicable attainment date, December 31, 2011. This determination is based on quality assured and certified ambient air quality date for the 2009-2011 monitoring period. Second, EPA is determining that the Liberty-Clairton Area has continued to attain the 1997 annual PM<INF>2.5</INF> NAAQS, based on quality-assured and certified ambient air quality data for the 2010-2012 monitoring period. The latter "clean data determination" suspends the requirement for the Liberty-Clairton Area to submit an attainment demonstration, reasonably available control measures (RACM), reasonable further progress (RFP), and contingency measures related to attainment of the 1997 annual PM<INF>2.5</INF> NAAQS for so long as the area continues to attain the 1997 annual PM<INF>2.5</INF> NAAQS. These determinations do not constitute a redesignation to attainment. The Liberty-Clairton Area will remain designated nonattainment for the 1997 annual PM<INF>2.5</INF> NAAQS until such time as EPA determines that the Liberty-Clairton Area meets the Clean Air Act (CAA) requirements for redesignation to attainment, including an approved maintenance plan. These actions are being taken under the CAA.