Syllabus
(c) The EPA asks the Court to defer to its most recent rule providing that “adjacent wetlands are covered by the [CWA] if they ‘possess a significant nexus to’ traditional navigable waters” and that wetlands are “adjacent” when they are “neighboring” to covered waters. Brief for Respondents 32, 20. For multiple reasons, the EPA’s position lacks merit. Pp. 22–27.
(1) The EPA’s interpretation is inconsistent with the CWA’s text and structure and clashes with “background principles of construction” that apply to the interpretation of the relevant provisions. Bond v. United States, 572 U. S. 844, 857. First, “exceedingly clear language” is required if Congress wishes to alter the federal/state balance or the Government’s power over private property. United States Forest Service v. Cowpasture River Preservation Assn., 590 U. S. ___, ___. The Court has thus required a clear statement from Congress when determining the scope of “the waters of the United States.” Second, the EPA’s interpretation gives rise to serious vagueness concerns in light of the CWA’s criminal penalties, thus implicating the due process requirement that penal statutes be defined “ ‘with sufficient definiteness that ordinary people can understand what conduct is prohibited.’ ” McDonnell v. United States, 579 U. S. 550, 576. Where penal statutes could sweep broadly enough to render criminal a host of what might otherwise be considered ordinary activities, the Court has been wary about going beyond what “Congress certainly intended the statute to cover.” Skilling v. United States, 561 U. S. 358, 404. Under these two principles, the judicial task when interpreting “the waters of the United States” is to ascertain whether clear congressional authorization exists for the EPA’s claimed power. Pp. 22–25.
