On December 9, 2013, eight northeastern states petitioned EPA under § 176A of the Clean Air Act to add nine upwind states – Illinois, Indiana, Kentucky, Michigan, North Carolina, Ohio, Tennessee, Virginia, and West Virginia – to the Ozone Transport Region (OTR). The petition alleges that “interstate transport of air pollution from [the nine upwind states] contributes significantly to violations of the 2008 ozone NAAQS within the OTR, including within” the eight northeastern states. In support of their petition, the northeastern states filed a Technical Support Document, which relies heavily on the air quality modeling preformed by EPA in support of CSAPR.

The OTR was established by § 184 of the Clean Air Act as part of the 1990 Amendments to address nonattainment with the ozone NAAQS in northeastern states. EPA has 18 months to consider the petition and is required to allow for public participation through notice and comment.

The eight northeastern states are Connecticut, Delaware, Maryland, Massachusetts, New Hampshire, New York, Rhode Island, and Vermont. The petition comes one day before the Supreme Court is scheduled to hear oral arguments in EPA v. EME Homer City Generation, L.P.