Approval and Promulgation of Implementation Plans; Connecticut: Prevention of Significant Deterioration; Greenhouse Gas Permitting Authority and Tailoring Rule Revision

EPA is taking final action to approve a revision to the State Implementation Plan (SIP), submitted by Connecticut Department of Environmental Protection (DEP) to EPA on December 9, 2010, for parallel processing. DEP submitted the final version of this SIP revision on February 9, 2011. The SIP revision, which incorporates updates to DEP's air quality regulations, includes two significant changes impacting the regulation of greenhouse gases (GHG) under Connecticut's New Source Review (NSR) Prevention of Significant Deterioration (PSD) program. First, the revision provides Connecticut with authority to issue PSD permits governing GHG. Second, the SIP revision establishes appropriate emission thresholds for determining which new stationary sources and modification projects become subject to Connecticut's PSD permitting requirements for their GHG emissions. The first change is necessary because Connecticut is required to apply its PSD program to GHG- emitting sources, and unless it does so (or unless EPA promulgates a federal implementation plan (FIP) to do so), such sources will be unable to receive preconstruction permits and therefore may not be able to construct or modify. The second change is necessary, because without it, PSD requirements would apply at the 100 or 250 ton per year (tpy) levels otherwise provided under the Clean Air Act (CAA or Act), which would overwhelm Connecticut's permitting resources. EPA is approving Connecticut's February 9, 2011, SIP revision because the Agency has made the determination that this SIP revision is in accordance with the CAA and EPA regulations, including regulations pertaining to PSD permitting for GHG. Additionally, EPA is responding to adverse comments received on EPA's January 6, 2011, proposed approval of Connecticut's December 9, 2010, SIP revision.