In 2003 the United States Court of Appeals for the Eleventh Circuit decided two cases concerning the Clean Air Act, holding that provisions allowing the Environmental Protection Agency (“EPA”) to address compliance issues through the issuance of administrative compliance orders are unconstitutional2 and that the Clean Air Act does not waive the United States’ defense of sovereign immunity in an action for punitive penalties for past violations of air pollution laws. The court also considered for the first time the circumstances under which a state enforcement action would preempt a citizen suit under the Clean Water Act. This Article also discusses a district court case that decides two issues which have not yet been addressed by the Eleventh Circuit: (1) whether and to what extent the Supreme Court’s decision in Solid Waste Agency of Northern Cook County v. United States Army Corps of Engineers changed the definition of “navigable waters” under the Clean Water Act and the Oil Pollution Act;6 and (2) what standards, if any, apply to a government cleanup under the Oil Pollution Act for the purpose of determining whether the cleanup costs were reasonable. This Article then discusses a district court case holding that a county government was acting as a market participant in the solid waste collection and disposal markets, and thus, its contract with a private waste hauler was not subject to review under the Commerce Clause of the United States Constitution. Finally, this Article briefly reviews a district court holding remanding an Army Corps of Engineers issuance of a “Finding of No Significant Impact” under the National Environmental Policy Act in connection with a dam project in Alabama, and an Eleventh Circuit decision awarding litigation costs to plaintiffs under the Clean Water Act for fees paid to an expert for monitoring compliance with a consent order.