Michigan Supreme Court Challenges Enbridge Pipeline Tunnel Permit

The Michigan Supreme Court has directed state regulators to reevaluate a crucial permit that advanced plans for a tunnel to transport an oil pipeline below portions of the Great Lakes. The 6-1 decision casts doubt on the future of the 73-year-old pipeline owned by Enbridge, a Canadian energy transportation firm. This pipeline transports petroleum from Superior, Wisconsin, to Sarnia, Ontario. The segment in question, known as Line 5, stretches 4 miles (6 kilometers) along the Straits of Mackinac’s bottom, where Lakes Huron and Michigan converge.

Enbridge aims to encase the pipeline within a tunnel beneath the straits. Environmental advocates and Michigan Governor Gretchen Whitmer wish to relocate the pipeline away from the waterway entirely, citing potential catastrophic effects of a spill on the Great Lakes and adjacent regions. The Michigan Public Service Commission authorized the tunnel’s construction permit in 2023. Subsequently, four Michigan tribal nations along with several environmental organizations filed lawsuits. On Friday, the Michigan Supreme Court concluded that during the permit’s approval, regulators neglected to evaluate whether the tunnel project would prolong the pipeline’s lifespan, thereby increasing environmental risk.

Additionally, the ruling highlighted inconsistencies in the Public Service Commission’s comparison of pipeline alternatives, such as oil transport via trucks or trains, and failed to address the tunnel’s impact on fishing, boating, and other public trust rights tied to the Great Lakes.

Opponents assert that undertaking such a project is unprecedented and would transform the Straits of Mackinac—a sacred site for the Indigenous Anishinaabe tribes—into a construction zone for years. David Gover, an attorney with the Native American Rights Fund, stated, “Whether Line 5 is suspended in the water or encased in a tunnel, it is simply a terrible idea to pump more than half a million barrels of oil every day through the middle of the Great Lakes.”

Following the ruling, Enbridge is considering its legal options and expressed disappointment over the project’s delay, which has been under review for nearly a decade. The company claims this tunnel would bolster environmental protection around the Great Lakes while sustaining essential energy reliability for the region, according to Enbridge spokesman Ryan Duffy.

Enbridge proposed the pipeline tunnel approximately ten years ago, following an incident in which a ship anchor damaged part of the pipeline. The company maintains that the tunnel would significantly decrease the risk of an oil spill. However, environmentalists contend that constructing the tunnel beneath the Straits of Mackinac’s bottom would produce noise, vibrations, and lasting environmental degradation.

In separate court proceedings, Governor Whitmer and other state officials have been striving since 2020 to cease pipeline operations under the straits.