This October Term, the U.S. Supreme Court will be asked to weigh in on three and possibly all four of its pending original jurisdiction controversies over interstate waters. The Court’s past judgments and opinions have established little in the way of “federal common law” governing the states’ interests in shared waters. But they have established this much: these interests vest in states-as-states directly under the U.S. Constitution, even if the Court itself is reluctant to specify the interests with much precision or to enjoin violations thereof.

In County of Maui v. Hawaii Wildlife Fund, the U.S. Supreme Court held, 6-3, that the Clean Water Act requires a national pollutant discharge elimination system permit “when there is the functional equivalent of a direct discharge.” The Court also decided Atlantic Richfield Co. v. Christian, holding, 7-2, that landowners adjacent to a Superfund site were potentially responsible parties under the Comprehensive Environmental Response, Compensation, and Liability Act.