Air Plan Approval; TN; Reasonably Available Control Measures and Redesignation for the TN Portion of the Chattanooga 1997 Annual PM2.5

The Environmental Protection Agency (EPA) is proposing two separate but related actions pertaining to the Tennessee portion of the Chattanooga nonattainment area for the 1997 annual fine particulate matter (PM2.5) national ambient air quality standards (NAAQS) (hereinafter referred to as the ``Chattanooga TN-GA-AL Area'' or ``Area''). First, EPA is proposing to approve the portion of the attainment plan state implementation plan (SIP) revision submitted by the State of Tennessee, through the Tennessee Department of Environment and Conservation (TDEC), on October 15, 2009, that addresses reasonably available control measures (RACM), including reasonably available control technology (RACT), for the Tennessee portion of the Area. EPA is not proposing to act on the portions of the SIP revision that are unrelated to RACM. Second, EPA is supplementing the Agency's March 27, 2015, proposed approval of Tennessee's November 13, 2014, redesignation request for the Tennessee portion of the Area by proposing that approval of the RACM portion of the aforementioned SIP revision satisfies the applicable RACM requirements for redesignation under the Clean Air Act (CAA or Act).