American Farm Bureau Federation v. EPA (U.S. Supreme Court)

The Clean Water Act requires States to establish a “total maximum daily load” (TMDL) for pollutants in certain impaired waters. Pursuant to this authority and on behalf of six States and the District of Columbia, EPA established a complex TMDL governing the Chesapeake Bay’s 64,000-square mile watershed. In addition to setting total pollutant limits, however, the Chesapeake TMDL also purports to set thousands of sub-allocations among different categories of sources from different land uses, and to establish compliance deadlines backed by the threat of federal sanctions. We filed a petition asking whether such a far-reaching TMDL is authorized by the statute.