On May 27, EPA and the Army Corps of Engineers jointly issued a long-awaited final rule designed to clarify the scope of federal jurisdiction under the Clean Water Act by delineating the reach of the statutory term "waters of the United States," to which the agencies can regulate discharges. That language from the statute was the subject of complex Supreme Court decisions issued in 2001 and 2006, and the new rule is similarly expected to be challenged in court. The primary sources of controversy surrounding the rulemaking have involved the circumstances under which the federal agencies will exercise jurisdiction over tributaries to navigable waters, and over wetlands. According to EPA, the "Clean Water Rule" is anticipated to confirm previously uncertain federal authority over up to 60 percent of the nation's streams and millions of acres of wetlands, and will apply only to those waters with a "direct and significant" connection to larger bodies of water that are already protected. Opponents of the rule have argued that it will unduly expand federal influence; the House of Representatives voted to block the rule earlier this month, and a Senate panel is considering similar action.

The new rule has not yet been published in the Federal Register; a prepublication copy is available here