The Environmental Protection Agency (EPA) is taking direct final action to approve the 2006 24-hour fine particulate matter (PM<INF>2.5</INF>) 2008 base year emissions inventory portion of the State Implementation Plan (SIP) revision submitted by the State of Tennessee through the Tennessee Department of Environment and Conservation (TDEC) on October 18, 2013. The emissions inventory is part of Tennessee's October 18, 2013, attainment demonstration SIP revision that was submitted to meet Clean Air Act (CAA or Act) requirements related to the Knoxville nonattainment area for the 2006 24-hour PM<INF>2.5</INF> national ambient air quality standards (NAAQS), hereinafter referred to as "the Knoxville Area" or "Area." The Knoxville Area is comprised of Anderson, Blount, Knox, and Loudon Counties in their entireties and a portion of Roane County that includes the Tennessee Valley Authority's Kingston Fossil Plant.