In a significant legal victory for Michigan, the United States Supreme Court has ruled that the state’s lawsuit to shut down a portion of the aging Line 5 energy pipeline will remain in state jurisdiction. This decision, announced on April 22, 2026, underscores the growing concerns over the environmental risks associated with the pipeline, which has been in operation since 1953.
The Legal Battle Over Line 5
The case revolves around a 4.5-mile (6.4 km) segment of the Line 5 pipeline that traverses the Straits of Mackinac, connecting Lake Michigan and Lake Huron. Michigan’s attorney general, Dana Nessel, initiated the lawsuit in June 2019, aiming to invalidate the easement that permits Enbridge, the Canadian energy company operating the pipeline, to run this segment beneath the Great Lakes. In June 2020, Nessel secured a restraining order from Ingham County Judge James Jamo, effectively pausing operations until safety standards were met.
Enbridge later sought to transfer the case to federal court, claiming it had implications for trade between the United States and Canada. However, in June 2024, a three-judge panel from the Sixth Circuit Court of Appeals ruled that Enbridge had missed a critical 30-day window to change the jurisdiction of the case. Justice Sonia Sotomayor, delivering the unanimous opinion, stated that the company’s delay was untenable, thereby reaffirming the state court’s authority over the matter.
Environmental Concerns and Pipeline Safety
The issue of safety surrounding Line 5 has been contentious, particularly since revelations in 2017 that Enbridge had been aware of significant gaps in the protective coating of the pipeline since 2014. The situation escalated in 2018 when a boat anchor caused damage to the line, heightening fears of a potential catastrophic spill in the Great Lakes. The Michigan Department of Natural Resources, under Governor Gretchen Whitmer, formally revoked the easement for Line 5 in 2020, a decision that remains under appeal in federal court.
Despite a federal ruling that blocked Whitmer’s revocation attempt, doubts linger regarding the implications for Nessel’s state court case. Enbridge contends that the federal court has already determined that federal regulators, not the state, bear responsibility for the safety of Line 5, and that no significant issues have been identified to warrant a shutdown.
Plans for a Replacement Tunnel
In response to ongoing safety concerns, Enbridge is pursuing permits to encase the pipeline in a protective tunnel beneath the Straits of Mackinac. In 2023, the Michigan Public Service Commission granted the necessary permits, but this move has been met with resistance from a coalition of environmental organisations and Michigan tribes, who have filed their own lawsuit to challenge the state permits. The state Supreme Court is currently deliberating on this matter.
Enbridge also faces challenges in Wisconsin, where a federal judge ordered the company to shut down a segment of Line 5 that crosses the Bad River Band of Lake Superior’s reservation. While Enbridge has appealed this decision, it has commenced rerouting the pipeline around the reservation, despite ongoing legal action from the Bad River Band and environmental groups that argue the reroute will cause significant damage to the ecosystem.
Why it Matters
The Supreme Court’s decision to keep the Line 5 case within state jurisdiction represents a critical juncture in the ongoing fight over pipeline safety and environmental protection. As communities and states grapple with the risks posed by aging energy infrastructure, this ruling not only highlights the importance of local governance in environmental issues but also sets a precedent for future legal battles involving energy companies and state authorities. The ramifications of this case will resonate beyond Michigan, influencing how similar disputes are managed across the United States, particularly in regions where environmental sustainability and economic interests are at odds.
