The Michigan Supreme Court vacated the state's approval for Enbridge's proposed Line 5 tunnel project.
The Michigan Supreme Court issued a 6-1 decision on Friday, July 31, vacating the 2023 Michigan Public Service Commission order that authorized Enbridge to relocate the four-mile Straits of Mackinac section of Line 5 into a concrete-lined tunnel. Justice Elizabeth Welch wrote for the majority, stating that regulators improperly narrowed the environmental review and failed to consider the project's potential harm to the Great Lakes. The court ruled that the commission must consistently compare the tunnel with possible alternatives and separately examine the public's rights to use the Great Lakes. This decision sends the long-delayed infrastructure project back to utility regulators for a broader review. While the commission had previously approved the tunnel, the ruling highlights that the tunnel has not yet received the rigorous environmental review required by Michigan law. Enbridge spokesperson Ryan Duffy expressed disappointment and is currently assessing legal options. The project remains a significant infrastructure goal, but the court's ruling requires a more comprehensive analysis of the tunnel's polluting effects on the air, water, and natural resources.