Line 5 Pipeline

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 future of a tunnel project for the Line 5 pipeline in the Straits of Mackinac has been a years-long cycle of litigation and environmental controversy. Here's where things stand.

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.

At a pivotal moment for a proposal to encase a petroleum pipeline in a tunnel under the Straits of Mackinac, opponents of the plan rallied at the Michigan Capitol.

The leak was caused when a truck — which Enbridge said was unoccupied — rolled over an open excavation site for a Line 5 valve project, over a natural gas transmission line.

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.”

The state's high court says the Michigan Public Service Commission failed to fully consider the project's potential environmental impacts.

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.

Line 5 fans and foes have been fighting for years over the best way to reduce oil spill risks from the lake bottom pipeline, with some supporting the tunnel and others calling for a pipeline shutdown