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.
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“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.
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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.