On March 21, 2012, the U.S. Supreme Court issued its opinion in Sackett v. U.S. Environmental Protection Agency and settled the question of whether “pre-enforcement” judicial review is available for an administrative compliance order issued under §309(a)(3) of the Clean Water Act (CWA). Despite much speculation by commenters, questions remain as to what the decision means for enforcement under the affected programs. This Article examines enforcement mechanisms that may be affected by the Sackett holding and the possible consequences to enforcers and the regulated community under the CWA and other environmental statutes administered by EPA.