Michigan’s highest court has ordered state energy regulators to redo their environmental review of Enbridge’s Line 5 tunnel project beneath the Straits of Mackinac.
The Michigan Supreme Court’s Friday ruling marks a major setback for the project, which saw a burst of momentum in July when Democratic Gov. Gretchen Whitmer’s administration issued key permits for construction.
Enbridge plans to replace a four-mile dual pipeline segment on the bottom of the straits with a single pipeline encased in a cement tunnel beneath the lake bed. The proposed 21-foot-diameter tunnel is meant to address long-standing concerns that the existing aging pipes are at risk of spilling oil into the Great Lakes.
In a 6-1 decision, the state Supreme Court tossed out the Michigan Public Service Commission’s order approving the project.
