MATS Remain in Effect Pending Agency Efforts on Costs

On Tuesday, the D.C. Circuit decided to remand the Mercury and Air Toxics Standards (MATS) to EPA without vacating the rule.  Last month, the Supreme Court held that EPA needed to consider costs before deciding whether a regulation is appropriate and necessary, finding that EPA acted unreasonably in deeming cost irrelevant to its MATS rule. The Supreme Court sent the rule back to the D.C. Circuit.  By remanding without vacatur, the D.C. Circuit denied the requests of multiple state and industry petitioners to throw out the rule entirely at this point.  EPA intends to issue its final finding by April 15, 2016.