Daimler Trucks North America LLC v. Environmental Protection Agency

The D.C. Circuit dismissed as moot truck engine manufacturers' lawsuit challenging four certificates of conformity EPA issued to another engine manufacturer pursuant to an interim final rule that allowed certificates to be issued to 2012 and 2013 model-year engines even if the engines fail to conform to EPA's emission standard for nitrogen oxides provided the manufacturer pays a non-conformance penalty (NCP). The interim final rule was vacated by the court in 2012, and three months later, EPA replaced the interim rule with a final NCP rule establishing new—and higher—penalties. As a result, the four certificates at issue no longer require that the manufacturer pay the NCPs established in the interim final rule—the subject of the lawsuit. In addition, the certificates expired at the end of the 2012 model year. The certificates, therefore, have no effect whatsoever and the lawsuit is moot.