EPA is approving revisions to the Tennessee State Implementation Plan (SIP) submitted on September 8, 2006. This revision incorporates provisions related to the implementation of EPA's Clean Air Interstate Rule (CAIR), promulgated on May 12, 2005, and subsequently revised on April 28, 2006, and December 13, 2006, and the CAIR Federal Implementation Plan (FIP) concerning Sulfur Dioxide (SO<INF>2</INF>), Nitrogen Oxides (NO<INF>X</INF>) annual, and NO<INF>X</INF> ozone season emissions for the State of Tennessee, promulgated on April 28, 2006, and subsequently revised December 13, 2006. On February 8, 2007, Tennessee requested that EPA only act on a portion of the September 8, 2006 submittal as an abbreviated SIP. Consequently, EPA is approving an abbreviated SIP revision that addresses the methodology to be used to allocate annual and ozone season NO<INF>X</INF> allowances under the CAIR FIPs and opt-in provisions for the SO<INF>2</INF>, NO<INF>X</INF> annual, and NO<INF>X</INF> ozone season trading programs. EPA is not making any changes to the CAIR FIP, but is amending, to the extent EPA approves Tennessee's SIP revision, the appropriate appendices in the CAIR FIP trading rules simply to note that approval.