Limited Approval of Implementation Plans of Indiana: Clean Air Interstate Rule

EPA is promulgating a limited approval of a revision to the Indiana State Implementation Plan (SIP) submitted on February 28, 2007. 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 Plans (CAIR FIP) concerning SO<INF>2</INF>, NO<INF>X</INF> annual, and NO<INF>X</INF> ozone season emissions for the State of Indiana, promulgated on April 28, 2006, and subsequently revised December 13, 2006. EPA is not making any changes to the CAIR FIP. It is, however, to the extent EPA approves Indiana's SIP revision, amending the appropriate appendices in the CAIR FIP trading rules simply to note that approval. On September 20, 2007, Indiana requested that EPA act on a portion of the February 28, 2007, submittal as an "abbreviated SIP." Consequently, EPA is approving this abbreviated SIP revision, which addresses: The applicability provisions for the NO<INF>X</INF> ozone season trading program and supporting definitions of terms; the methodology to be used to allocate NO<INF>X</INF> annual and ozone season NO<INF>X</INF> allowances and supporting definitions of terms; the compliance supplement pool (CSP) provisions for the NO<INF>X</INF> annual trading program; and provisions for SO<INF>2</INF> and NO<INF>X</INF> opt-in units, all under the CAIR FIP.