Unclear: Scope of federal authority at issue. (Photo courtesy of the U.S. Fish and Wildlife Service)

The Supreme Court's June 19 decision on wetlands cases didn't map limits of federal regulatory authority as clearly as many hoped. Now agencies, courts, contractors and environmental groups are struggling with how to interpret the ruling.

In two consolidated cases, Rapanos v. U.S. and Carabell v. U.S. Army Corps of Engineers, the justices produced five opinions, but none had support from more than four justices, one short of a majority. The key opinion was by Associate Justice Anthony Kennedy, who agreed with four conservative colleagues that the case should be sent back to lower courts. Echoing a 2001 ruling, Kennedy also said that a wetland must have a "significant nexus to navigable waters" to be subject to the federal Clean Water Act.

After the Rapanos decision, "I would say there's going to be confusion, if not more than there was before," says Leah Pilconis, senior environmental counsel for the Associated General Contractors. She says regulatory scope is an important issue for contractors, who want to know whether they must calculate costs of obtaining a federal wetlands permit as they prepare bids on projects.

Jim Murphy, National Wildlife Federation wetlands and water resources counsel, contends the decision "requires continued broad Clean Water Act protection [but has] enough twists and turns that there are going to be a lot of questions and a lot of litigation and...fighting over what exactly it means."

Senior Environmental Protection Agency and Army civil works officials told a Senate hearing Aug. 1 that EPA and the Corps of Engineers are working on "guidance" to clarify federal wetlands authority. A Corps spokesman says the guidance may be out within a month.

AGC wants the agencies to go further, and start drafting a formal rule to clear up the regulatory questions. Rulemaking is "a logical step," says Gary Suskauer, National Association of Home Builders environmental policy analyst. "We need something," he adds.

Jeanne Christie, executive director of the Association of State Wetland Managers, says the idea of a rule is "reasonable," but could take months. "I think without rulemaking, I would not want to be a permit applicant in one of those grey areas," she adds.

Federal courts also are drawing on Rapanos. The U.S. Court of Appeals for the 9th Circuit ruled Aug. 10 for Northern California River Watch that a quarry pit filled with water from an aquifer had a "significant nexus" to the Russian River and is covered by the Clean Water Act.

But a federal district court in Texas ruled June 28 that a Chevron Pipe Line Co. oil discharge didn't reach U.S. "navigable waters." It said Kennedy's "significant nexus" test was "ambiguous."

Sen. James Jeffords (I-Vt.) wants Congress to clarify the muddy regulatory landscape. But action isn't likely in this session, which will be shortened because of November's elections.