California v. EPA

The D.C. Circuit Court of Appeals granted the U.S. Environmental Protection Agency’s (EPA’s) motion for voluntary vacatur of a final rule published on January 13, 2021 that adopted a numerical threshold and other criteria for determining when a source category’s greenhouse gas emissions significantly contribute to air pollution that endangers public health or welfare, making the source category subject to new source performance standards. EPA acknowledged in its motion that it had promulgated the rule without providing notice and opportunity to comment on the rule’s central elements. Because the rule therefore was unlawful and EPA did not intend to cure the procedural defect, EPA requested vacatur and remand.

State and local governments challenged EPA’s final rule that set a threshold for determining whether greenhouse gas emissions from new source performance standard (NSPS) source categories contribute significantly to dangerous air pollution. The rule would require that a source category’s emissions constitute 3% of U.S. greenhouse gas emissions in order to be regulated in the NSPS program.