A federal court last week granted a motion barring the U.S. Army Corps of Engineers and Environmental Protection Agency (EPA) from enforcing the Clean Water Rule, which critics say is “exceptionally expansive.”

A three-judge panel at the U.S. Court of Appeals for the Sixth Circuit on Oct. 9 granted the stay sought by 31 states and state agencies that are challenging the legality of the rule.

Judge David W. McKeague delivered the order of the court in which Judge Richard Allen Griffin joined. However, Senior Judge Damon J. Keith delivered a separate dissent on technical grounds, saying he did not believe it “prudent for a court to act before it determines that it has subject-matter jurisdiction.”

In their complaint, the states said the rule’s new definition of “Waters of the United States” (or WOTUS) violates provisions of the Clean Water Act, the National Environmental Policy Act, and the U.S. Constitution. The states want the rule vacated and the EPA and Corps enjoined from enforcing a new definition of “Waters of the United States.”

The appellate court concluded that petitioners demonstrated “substantial possibility of success on the merits of their claims,” including that the rule’s treatment of tributaries, “adjacent waters,” and waters having a “significant nexus” to navigable waters is at odds with a U.S. Supreme Court ruling, where the high court vacated the Sixth Circuit’s upholding of wetlands regulation by the Army Corps. of Engineers.

“A stay temporarily silences the whirlwind of confusion that springs from uncertainty about the requirements of the new Rule and whether they will survive legal testing,” wrote Judge McKeague for the court.

“In granting the stay, the Court described the rule as ‘facially suspect,’” said West Virginia Attorney General Patrick Morrisey, who has led the coalition that is opposing the rule. “This solidly reaffirms our belief that we have a strong case on the merits and that the courts will ultimately strike down this burdensome regulation. We look forward to continuing to challenge this rule’s legality in court and are confident we will prevail.”

The motion follows a preliminary injunction granted by Judge Ralph Erickson of the U.S. District Court for the District of North Dakota on Aug. 28—the day the June 29–finalized rule went into effect.

States and entities challenging the rule include: Alabama, Alaska, Arkansas, Colorado, Florida, Georgia, Idaho, Indiana, Kansas, Kentucky, Louisiana, Michigan, Mississippi, Missouri, Montana, Nebraska, Nevada, North Dakota, Ohio, Oklahoma, South Carolina, South Dakota, Tennessee, Texas, Utah, West Virginia, Wisconsin, Wyoming, the North Carolina Department of Environment and Natural Resources, the New Mexico Environmental Engineer, and the New Mexico State Engineer.

Electric utilities have also expressed concerns that water near plants, such as water drainage ditches and cooling ponds, may be considered U.S. waters.

The court will still need to issue a full ruling on the case.

Sonal Patel, associate editor (@POWERmagazine, @sonalcpatel)