On April 29, 2014, the U.S. Supreme Court reversed the D.C. Circuit opinion vacating CSAPR.

The Court's opinion concludes:

"In sum, we hold that the CAA does not command that States be given a second opportunity to file a SIP after EPA has quantified the State’s interstate pollution obligations. We further conclude that the Good Neighbor Provision does not require EPA to disregard costs and consider exclusively each upwind State’s physically proportionate responsibility for each downwind air quality problem. EPA’s cost-effective allocation of emission reductions among upwind States, we hold, is a permissible, work- able, and equitable interpretation of the Good Neighbor Provision.

For the reasons stated, the judgment of the United States Court of Appeals for the D. C. Circuit is reversed, and the cases are remanded for further proceedings consistent with this opinion."

View the entire opinion below.

• Environmental Protection Agency et al. v. EME Homer City Generation, L. P., et al. (PDF)(58 pp, 268 K, April 29, 2014)
  Certiorari to the United States Court of Appeals for the District of Columbia Circuit