WASHINGTON — The Federal Energy Regulatory Commission issued a stop work order on the Atlantic Coast Pipeline, ordering Atlantic Coast Pipeline LLC and Dominion Energy Transmission Inc. to provide an interim right-of-way and work area stabilization plan.

The order halts construction of the $5.5 billion project, which includes 600 miles of buried pipeline from West Virginia into eastern North Carolina.

The U.S. Court of Appeals for the Fourth Circuit issued an order on Aug. 6 vacating a right-of-way permit from the National Park Service and the Incidental Take Statement issued by the U.S. Fish and Wildlife Service.

“Commission staff cannot predict when NPS or FWS may act or whether NPS will ultimately approve the same route,” Office of Energy Projects Director Terry Turpin said in a letter to Dominion Energy.

“Should NPS authorize an alternative crossing location, Atlantic may need to revise substantial portions of the ACP route across non-federal or federal lands, possibly requiring further authorizations and environmental review.”

Aaron Ruby, spokesman for Atlantic Coast Pipeline and Dominion Energy, said they are working with key agencies to resume construction as soon as possible.

“The Atlantic Coast Pipeline has been the most thoroughly reviewed infrastructure project in the history of our region. The recent action by the courts and FERC are further evidence of this unprecedented scrutiny and the high standard that is being applied to this project,” he said.

The interim right-of-way and work area stabilization plan have to be submitted within five days for review and written approval by the Turpin or a designee of the Office of Energy Projects.