By Lesley Foxhall Pietras

On June 24, 2013, the U.S. Supreme Court granted the petitions for writs of certiorari filed by the U.S. Environmental Protection Agency (“EPA”) and the American Lung Association in the litigation involving EPA’s Cross-State Air Pollution Rule (“CSAPR”). The CSAPR sets limits on sulfur dioxide and nitrogen oxides from power plants in 28 upwind states in the eastern part of the country. On August 21, 2012, in a 2-1 decision, the D.C. Circuit vacated the rule, concluding that EPA exceeded its authority under the Clean Air Act by forcing states to reduce their emissions by more than an amount determined to be their “significant contribution” to nonattainment in other states, and that EPA improperly issued federal implementation plans to implement the CSAPR without providing the states with an initial opportunity to implement the required reductions for sources within their borders.

The Supreme Court limited its review to the questions presented in EPA’s petition, which are: (1) whether the D.C. Circuit lacked jurisdiction to consider the challenges on which it granted relief; (2) whether states are excused from adopting state implementation plans prohibiting emissions that “contribute significantly” to air pollution problems in other states until after EPA has adopted a rule quantifying each state’s interstate pollution obligations; and (3) whether EPA permissibly interpreted the statutory term “contribute significantly” so as to define each upwind state’s “significant” interstate air pollution contributions in light of the cost-effective emissions reductions it can make to improve air quality in polluted downwind areas, or whether the Clean Air Act instead unambiguously requires EPA to consider only each upwind state’s physically proportionate responsibility for each downwind air quality problem.

The two consolidated cases the Supreme Court agreed to hear are EPA v. EME Homer City (No. 12-1182) and American Lung Association v. EME Homer City Generation (No. 12-1183). Both the Supreme Court’s order (pdf) and EPA’s petition (pdf) are available online.