Mountain Valley pipeline faces another setback after the 4th U.S. Circuit Court of Appeals vacated a water permit necessary for the development of the $6.2 billion pipeline in West Virginia.

According to a Reuters report, the court found defects in the review conducted by the West Virginia Department of Environmental Protection before issuing the permit, adding the agency needs to reconsider the permit before construction can resume and the proposed 303-mile pipeline can cross the state's wetlands and streams.

Equitrans Midstream Corp, the developer, stated it is reviewing the decision, adding that the project has undergone "unprecedented" environmental reviews and is being built to "higher environmental standards than any similar project" in the state.

The Monday ruling followed a 2022 lawsuit by Landowners and environmental groups, including the Sierra Club, that compelled the court to toss the permit, stating that the agency ignored Equitrans' history of violating state water regulations when it issued the permit under the Clean Water Act.

A unanimous three-judge panel of the 4th Circuit agreed that these violations warranted closer scrutiny, with Sierra Club Dirty Fuels Director Patrick Grenter stating that the decision affirms "MVP can't be trusted to comply with the most basic standards of reasonable conduct."

The pipeline is almost complete, according to Equitrans, but opponents argue that the figure fails to account for the full scope of work needed to complete the project, with the bulk of the unfinished portions of the pipeline either crossing streams and rivers or go through the Jefferson National Forest in Virginia.

The federal government is currently considering whether to reissue a permit for the forest crossing since the 4th Circuit upheld a Virginia water permit needed for stream crossings in the state last month.