On Thursday, Boyden Gray & Associates argued on behalf of Kansas and Nebraska in the U.S. Court of Appeals for the D.C. Circuit. The case is a challenge to EPA’s vehicular emissions model, MOVES2014. The model produces erroneous emissions estimates that will make it harder for States to comply with EPA’s air quality standards.

The States argued before Judges Millett, Wilkins, and Randolph that the model was promulgated unlawfully without notice and opportunity for public comment. EPA took the position that notice and comment rulemaking was not required because the model’s Official Release was not a substantive rule but only a policy statement. The States replied that Official Release is a binding rule because it is written in mandatory terms and because under the Clean Air Act, the States are presumptively required to use EPA’s model.

A significant portion of the 70-minute argument concerned the constitutional standing of the States, which will be required to use the model in their state implementation plans when they are designated as being in nonattainment with EPA’s new National Ambient Air Quality Standard for ozone.

Adam Gustafson argued the case for the States and their co-petitioners, the Energy Future Coalition and Urban Air Initiative.

The case is Kansas v. EPA, No. 14-1268 (D.C. Cir.). An audio recording of the oral argument is available here. The briefs are available here.