Approval and Promulgation of Air Quality Implementation Plans; Maryland; Baltimore Nonattainment Area Determinations of Attainment of the 1997 Annual Fine Particulate Standard

EPA is proposing to make two determinations regarding the Baltimore fine particulate matter (PM<INF>2.5</INF>) nonattainment area (hereafter referred to as "the Baltimore Area" or "Area"). First, EPA is proposing to determine that the Area has attained the 1997 annual PM<INF>2.5</INF> National Ambient Air Quality Standard (NAAQS). This proposed clean data determination is based upon complete, quality- assured and certified ambient air monitoring data for the 2008-2010 period showing that the Area has monitored attainment of the 1997 annual PM<INF>2.5</INF> NAAQS and data available to date for 2011 in EPA's Air Quality System (AQS) database that show the Area continues to attain. If EPA finalizes this proposed clean data determination, the requirements for the Area to submit an attainment demonstration and associated reasonably available control measures (RACM), a reasonable further progress (RFP) plan, contingency measures, and other planning State Implementation Plan (SIP) revisions related to the attainment of the standard shall be suspended for so long as the Area continues to attain the annual PM<INF>2.5</INF> NAAQS. EPA is also proposing to determine, based on quality-assured and certified monitoring data for the 2007-2009 monitoring period, that the Area has attained the 1997 annual PM<INF>2.5</INF> NAAQS by its applicable attainment date of April 5, 2010. In addition, EPA is withdrawing the July 31, 2009 (74 FR 38161) proposed clean data determination for the Baltimore Area. These actions are being taken under the Clean Air Act (CAA).