West Virginia has officially thrown out Mountain Valley Pipeline’s Section 401 water quality certification (WQC) and will start over with a review of the project’s application after the U.S. Court of Appeals for the Fourth Circuit granted the agency’s motion to invalidate the certificate.

WVDEP filed the motion last month in response to five environmental groups that filed a petition for review of the agency’s March decision to issue the certificate. The groups argued that the agency ignored the project’s threat to the state’s environment.

In a decision welcomed by the challengers, the Fourth Circuit granted the WVDEP’s motion to vacate the WQC and remand the matter back to the agency for further review. WVDEP said last month it would scrap the certificate and reevaluate the application after it was determined that the information used to issue it needed closer evaluation. The decision also came after the environmental groups filed their court challenge and “out of an abundance of caution...to ensure that all aspects of the potential environmental impact of MVP are considered,” an agency spokesman said at the time.

The Federal Energy Regulatory Commission issued a certificate authorizing the project earlier this month, with the lone sitting Democrat, Commissioner Cheryl LaFleur, issuing a rare dissent. Despite that approval, MVP can’t move forward with construction until WVDEP makes a decision on the WQC, as it’s required to do under Section 401 of the Clean Water Act.

The petition for review was filed by Appalachian Mountain Advocates on behalf of the Sierra Club, West Virginia Rivers Coalition, Indian Creek Watershed Association, Appalachian Voices and the Chesapeake Climate Action Network. Representatives for the groups said the court is giving WVDEP a second chance at “truly protecting hundreds of West Virginia streams and rivers from the impacts of the massive Mountain Valley Pipeline.”

It’s unclear what another WQC review might mean for the 2 Bcf/d project’s timeline. MVP’s sponsors are still targeting a full in-service date of 4Q2018 and have said they’re willing to cooperate with WVDEP to determine if the company’s application meets federal requirements. The 300-mile pipeline would originate in Wetzel County, WV and move gas to an interconnect with the Transcontinental Gas Pipe Line in Virginia.

The development is the latest outcome from environmental groups’ efforts to frustrate shale gas infrastructure. Embolden by several denials of WQC for pipelines in New York, the groups have pushed for closer scrutiny at the state level.