The Michigan Supreme Court has thrown out state approval of Enbridge's proposed Line 5 tunnel beneath the Straits of Mackinac.
The court found the Michigan Public Service Commission failed to fully consider the project's potential environmental impacts, including whether the tunnel would extend the life of the petroleum pipeline and create additional environmental risks.
The court also said the commission didn't properly compare alternatives or consider impacts on what are termed "public trust resources," like the Great Lakes.
The case now goes back to the Public Service Commission for another review.
Editor's note: Enbridge is among Michigan Public's corporate sponsors.
