The U.S. Supreme Court has supported Michigan in a decision stating that the state’s legal action to close a portion of an old pipeline beneath a Great Lakes channel will remain in state court. Justice Sonia Sotomayor, speaking for the entire court, noted that Enbridge, a company based in Calgary, took too long to attempt to transfer the case to federal court.
This case is part of a complicated legal battle concerning a pipeline that has transported crude oil and natural gas liquids between Superior, Wis., and Sarnia, Ont., since 1953. Michigan Attorney General Dana Nessel initiated the lawsuit in state court in June 2019 to invalidate the easement allowing Enbridge to operate a 6.4-kilometer segment of the pipeline under the Straits of Mackinac, connecting Lake Michigan and Lake Huron.
Nessel, a member of the Democratic party, obtained a restraining order from Ingham County Judge James Jamo in June 2020, halting pipeline operations, although Enbridge resumed activities after meeting safety criteria. In 2021, Enbridge moved the case to federal court, arguing its impact on U.S. and Canadian trade. However, a three-judge panel from the 6th U.S. Circuit Court of Appeals sent the case back to Jamo in June 2024, citing Enbridge’s failure to meet a 30-day jurisdictional deadline.
The pipeline in question, known as Line 5, has raised concerns about a potential rupture in the section under the straits leading to a disastrous spill. The Michigan Department of Natural Resources, under Governor Gretchen Whitmer, a Democrat, revoked the Line 5 straits easement in 2020. Enbridge has filed a separate federal lawsuit contesting the revocation.
Enbridge is currently seeking permits to encase the pipeline section under the straits in a protective tunnel. While the Michigan Public Service Commission granted relevant permits in 2023, Enbridge still requires approval from the U.S. Army Corps of Engineers and the Michigan Department of Environment, Great Lakes, and Energy.
The pipeline is also at the center of a legal battle in Wisconsin. A federal judge in Madison directed Enbridge to shut down a segment of Line 5 running across the Bad River Band of Lake Superior’s reservation within three years. Enbridge has proposed rerouting the pipeline around the reservation and has appealed the shutdown order to the 7th U.S. Circuit Court of Appeals.