Last week, the U.S. Court of Appeals for the District of Columbia declined to grant a rehearing of EME Homer City Generation LP v. EPA, a case that challenged EPA’s Cross-State Air Pollution Rule (CSAPR). The court, in a 2-1 ruling in August, vacated the CSAPR. The court stated that EPA was exceeding its statutory authority, as the agency should allow states to develop their own rules to address emissions and CSAPR could have required states to account for more emissions than necessary. EPA hoped to challenge the ruling of the court and asked for an en banc hearing, so that the case could be heard before all eight of the circuit’s judges. However, a majority of the judges voted against the request, so the court will not rehear the case. The question now is whether EPA will take its challenge to the Supreme Court.