D.C. Circuit Upholds EPA's Decision to Deny Petition to Expand Ozone Transport Region

On April 23, 2019, the U.S. Court of Appeals for the D.C. Circuit unanimously upheld the Environmental Protection Agency’s decision to deny the petition of nine states to expand the northeast Ozone Transport Region to include additional upwind states. The states filed the petition in 2013, aruing that ozone transport from certain upwind states significantly contributes to violations of the 2008 National Ambient Air Quality Standards in the Ozone Transport Region. In 2017, EPA denied the petition, stating that other Clean Air Act provisions were more effective mechanisms to address remaining interstate ozone transport concerns. Eight states filed a petition for review of EPA’s denial of the petition, arguing that the action was unlawful and should be vacated. In its opinion, the D.C. Circuit finds that EPA’s denial of the states’ petition “complied with the Clean Air Act and was a reasonable exercise of the agency’s discretion.”