Line 5 Tunnel Project

The move by tribes follows the Whitmer administration's request for a state agency to review the same permits using new guidance from a Michigan Supreme Court ruling.

Gov. Gretchen Whitmer said the court ruling directs the state to "more thoroughly scrutinize" the plan to encase a segment of the pipeline in a tunnel buried beneath the Straits of Mackinac — and that should include reviews of permits that were already issued.

The controversial project looks to encase the Line 5 pipeline, which carries crude oil and natural gas liquids through the Straits of Mackinac, into a concrete tunnel.

The federal approval doesn’t mean construction can begin as the project remains tied up in state and federal court.

In a 6-1 ruling Friday, the Michigan Supreme Court’s found the tunnel's approval should have consider factors like alternatives to the project and harm to Michigan’s “public trust resources.”

State agencies said the pipeline tunnel construction would affect Native American burial sites, wetlands and threatened and endangered species but concluded the benefits of the tunnel outweigh the damages. The project remains tied up in court.

Opponents said they're worried about potentially unsafe conditions, like weak bedrock, high water pressure and dangerous gases beneath the Straits.

Michigan has been trying to shut down the controversial pipeline since 2019. A technical question before the court could seal its fate.

Environmental advocates says eyes are on Whitmer as the state mulls another permit for the project.

Public comments are due by the end of the week after the U.S. Army Corps of Engineers proposed a tunnel alternative last month.