The Clean Water Act (CWA) provides that regulations shall be issued "which require an owner or operator of a tank vessel or facility ... to prepare and submit ... a plan for responding, to the maximum extent practicable, to a worst case discharge, and to a substantial threat of such a discharge, of … a hazardous substance." EPA was sued for failure to fulfill this mandatory duty imposed by Congress. This regulatory action is being conducted under the terms of a consent decree entered into on March 12, 2020, which requires that a proposed action is signed within 24 months of the final agreement and that a final action follow within 30 months of the publication of the proposed rule. Subsequently, the Environmental Protection Agency proposed a regulatory action to require planning for worst case discharges of CWA hazardous substances under section 311(j)(5)(A). EPA published a final rule in March 2024 and met the terms of the Consent Decree.