A controversial plan to update Line 5 just suffered a major loss at the Michigan Supreme Court

In a win for opponents of Enbridge Energy’s Line 5 pipeline, the Michigan Supreme Court vacated a key permit last week for a proposed project that would replace a segment of the pipeline running underneath an environmentally-sensitive area of the Great Lakes, finding that a state commission did not examine the full scope of possible harm to the environment.

Following the 6-1 decision, the justices remanded the permit back to the Michigan Public Service Commission for a more thorough review, which likely extends the timeline for a decision on a project that’s already been mired in legal and procedural hurdles for years. 

Enbridge Energy received the permit in 2023 for its proposal to replace a segment of the oil and natural gas liquids pipeline — which connects lakes Michigan and Huron via the Straits of Mackinac — with a new one encased in a tunnel buried in the lakebed. Environmental groups and tribal nations appealed the decision, landing the case before the state’s highest court this year.

Writing for a nearly unanimous court in a 58-page opinion, Justice Elizabeth Welch said that the commission didn’t consider the full range of potential environmental harms, nor did it look at how the project would impact the public’s right to use the state’s natural resources, which includes the Great Lakes — protections granted under the state’s public trust doctrine.

“We cannot fault (the commission) for this failure, because there was little authority on this issue prior to our decision today. Even so, it was error,” the opinion stated.

Justices found that the commission incorrectly limited its scope of review under the Michigan Environmental Protection Act to just the tunnel, when it should have examined how the project would impact the broader pipeline. Line 5 transports crude oil and natural gas liquids 645 miles from Superior, Wisconsin, through Michigan to Sarnia, Ontario, with 4.5 miles of the pipeline crossing the straits. 

In its new review, the justices said that the public service commission must answer whether the tunnel project will extend the lifespan of the 73-year-old pipeline, and if it does, determine what impacts there are to the environment and to the public trust.

“It is impossible to prevent or mitigate an environmental risk without understanding the nature of that risk,” the justices wrote.

Lawyers for the plaintiffs — four tribal nations across Michigan and three environmental groups — argued that because the tunnel project would extend the pipeline’s lifespan, it causes harm by increasing the risk of oil spills along Line 5’s entirety and increased greenhouse gas emissions from the fossil fuels it transports.

“The court has made clear that our understanding of environmental harm, it’s a practical understanding, but it’s also a broad one,” said Chad Hughes, senior attorney for the Environmental Law & Policy Center, which argued with the plaintiffs. “There’s no requirement to narrowly focus on the physical location of the project. You look at the environmental harms where they happen.”

By broadening the scope of reviews under the Michigan Environmental Protection Act, opponents said conversations about shutting down the entire pipeline are finally a possibility. The justices wrote that “a meaningful examination” of alternatives can’t happen until the commission determines the full impacts of the project.

“The door has been kicked open to an imaginable future where we can talk about alternatives other than Line 5,” said President Whitney Gravelle of the Bay Mills Indian Community, one of the plaintiffs in the case.

In a statement, Enbridge spokesperson Ryan Duffy wrote that the company disagrees and is disappointed by the ruling, calling it an additional delay to a project that has already been under review for nearly a decade. Enbridge is reviewing the opinion and assessing legal options, he said.

“What remains unchanged is our commitment to operating Line 5 safely and responsibly, incorporating enhanced safety measures in the Straits, and protecting Michigan’s natural resources for generations to come,” the statement said.

The lone dissenting opinion from Justice Brian Zahra said that the court’s directive to consider the full scope of potential harms was “a moral hazard,” because state regulators already decided Line 5 was in the public interest when it approved construction more than 70 years ago. 

But Zahra agreed with the majority on the requirement to consider the public trust doctrine, and recommended that the commission use last month’s permit issuance from a separate state agency as a guide. The Department of Environment, Great Lakes and Energy said the necessity of the tunnel in preventing an oil spill in the Great Lakes outweighed other public interests.

Separate from the tunnel project, Line 5 faces legal challenges from groups that have fought to shut down the pipeline for years, including Governor Gretchen Whitmer’s administration. This spring, a unanimous ruling from the U.S. Supreme Court paved the way for state court proceedings on whether the aging pipeline can continue operating in the straits.

Last week’s ruling was also a significant win for public trust considerations, according to environmental lawyers. The public service commission declined to consider the public trust doctrine in its analysis prior to issuing its permit in 2023, a decision upheld by the Michigan Court of Appeals because it argued the commission “possesses only that authority bestowed upon it by statute.”

The justices reversed this ruling, agreeing in a concurrent case with plaintiff Flow Water Advocates that the state legislature grants the public service commission “the authority — and indeed, the responsibility — to consider the public trust doctrine.”

“It is elevating the rights of the public. It’s saying that the intergenerational equity that we promise our children will be there,” said Liz Kirkwood, executive director of Flow.

Gravelle with the Bay Mills Indian Community said this new consideration of the doctrine is a win for tribal treaty rights. Tribes in Michigan have long asserted that Line 5’s operation interferes with their rights to fight, hunt, and gather on treaty-ceded lands, which include the Straits of Mackinac.

“You can’t have a treaty right to fish if you don’t have healthy waterways for fish to spawn. You can’t have a treaty right to hunt if you’re cutting down forests and filling wetlands, you can’t have a treaty right to gather if you’re polluting waterways and watersheds that are impacting plant species that you rely on for ceremonial or medicinal purposes,” she said.

The court’s ruling reflects an Indigenous way of thinking that could shape future environmental reviews, Gravelle said.

“We have teachings in our culture that require us to think generations ahead: Is the decision I made today going to benefit seven generations from now?” she said. “We need more holistic, proactive decision-making from our state agencies moving forward. And so, I hope that’s the pathway carved.”