The oft-delayed and increasingly costly Mountain Valley Pipeline LLC (MVP) has encountered another legal setback, as the natural gas conduit’s stream-crossing permitting has again been put on hold pending an ongoing review by the U.S. Court of Appeals for the Fourth Circuit.

Mountain Valley Pipeline

The Fourth Circuit issued a stay Monday after hearing oral arguments in a case filed by environmental groups challenging the Nationwide Permit 12 (NWP 12) approvals issued to the embattled pipeline by the U.S. Army Corps of Engineers. 

The Army Corps recently renewed the project’s NWP 12 authority, which had been on hold following an unfavorable 2018 ruling from the Fourth Circuit. Environmental groups, led by the Sierra Club, wasted little time in asking the circuit court to rule against the new...