In yet another blow for the Mountain Valley Pipeline (MVP), the U.S. Army Corps of Engineers on Friday suspended authorization for the project to cross hundreds of streams and wetlands in Virginia, citing a recent decision from a federal appeals court that vacated a key permit.

In a letter to MVP, the Army Corps’ Norfolk District said that because the U.S. Court of Appeals for the Fourth Circuit vacated its verification of MVP’s compliance with the Nationwide Permit (NWP) 12 in West Virginia, it is “uncertain” whether the permit will be “available to authorize work for MVP in West Virginia. Therefore, the Norfolk District finds it appropriate to suspend your authorization and await clarity on this issue.”

MVP was directed to stop all activities in Virginia authorized under the NWP 12, which covers 383 separate stream crossings and 142 separate wetland crossings in the state. The company is allowed to stabilize any work in progress.

MVP also may request a meeting within 10 days of the suspension. Following a meeting, the Army Corps said it could move to reinstate, modify or revoke the authorizations under the NWP 12.

The NWP 12 is issued by the Army Corps and allows contractors to trench through streams and rivers under Section 404 of the Clean Water Act. The Fourth Circuit vacated the permit in a three page order and said a more detailed opinion would come soon about its decision.

Opposition groups challenged the permit, seizing on a special condition included in the NWP 12 in West Virginia, which requires all stream crossings be constructed within 72 hours.

For four proposed crossings in West Virginia’s Elk, Gauley, Greenbrier and Meadow rivers, MVP had planned to use the more environmentally protective but time-consuming “dry cut” crossing method, ostensibly violating the 72-hour special condition.

In vacating the NWP 12, the Fourth Circuit concluded that the Army Corps “lacked authority to substitute the ”dry cut’ requirement ”in lieu of’ West Virginia’s 72-hour temporal restriction,” citing federal law requiring that “if any part of a project requires an individual permit, then ”the NWP does not apply and all portions of the project must be evaluated as part of the individual permit process.’”

Environmental groups hailed Friday’s decision. They again called on FERC to halt all work on the pipeline because the order authorizing the project requires all federal and state permits for construction to take place anywhere along the 300-mile route. The Federal Energy Regulatory Commission stopped all work in August after the Fourth Circuit vacated key permits from the U.S. Forest Service and the Bureau of Land Management. That order was eventually lifted and most work was allowed to resume.

Plagued by ongoing legal challenges, permit issues, work stoppages and inclement weather, MVP has already raised its cost estimate for the project by about $1 billion to $4.6 billion.

The pipeline would move 2 Bcf/d of Appalachian natural gas to markets in the Southeast and Mid-Atlantic via an interconnect with the Transcontinental Gas Pipe Line in southwestern Virginia.