EPA has disapproved the interstate transport elements of the SIP for Ohio for the 2008 ozone NAAQS. 81 Fed. Reg. 38957 (June 15, 2016). Previously, on December 27, 2012, Ohio submitted its infrastructure SIP to EPA including portions concerning interstate transport. On October 16, 2014, EPA approved other portions of the SIP but did not act on the interstate transport portions. EPA issued its disapproval of the Ohio SIP, as well as Indiana’s, for failing to meet the following “prongs” of CAA §110(a)(2)(D)(i):

• Prong one: The SIP must include provisions prohibiting any source or other type of emissions activity in one state from contributing significantly to nonattainment of NAAQS in another state;

• Prong two: The SIP must include provisions prohibiting any source or other type of emissions activity in one state from interfering with the maintenance of the NAAQS in another state; and

• Prong three: The SIP must include provisions prohibiting any source or other type of emissions activity in one state from interfering with measures required to protect visibility.

EPA identified that Ohio did not meet the requirements for four reasons. First, EPA stated that the Ohio SIP submission lacked any technical analysis evaluating or demonstrating how emissions in Ohio impact air quality in other states under the 2008 ozone NAAQS. Second, EPA concluded that Ohio’s SIP did not demonstrate how state programs and rules provide sufficient controls on emissions to address interstate transport. Third, EPA criticized Ohio EPA’s reliance on CAIR, which was designed for the 1997 ozone NAAQS and which the D.C. Circuit recently held to be invalid. See EME Homer City Generation, L.P. v. EPA, 795 F.3d 118, 133 (D.C. Cir. 2015). Finally, EPA noted that it recently released technical data that it claims contradicts Ohio EPA’s conclusion that its SIP provides adequate protections to address interstate transport concerns. See August 4, Notice of Data Availability, 80 Fed. Reg. 46271.

This disapproval triggers the obligation under CAA §110(c) for EPA to promulgate a federal implementation plan (FIP) within two years of the disapproval if SIP revisions that address the deficiencies have not been approved. We will monitor Ohio’s response to this disapproval.