The fate of the Line 5 pipeline is at another critical juncture in its 70-plus year history. The pipeline carries more than 500,000 barrels of petroleum products daily across the Great Lakes region from Wisconsin into Canada, taking a path that runs along the bottom of the Straits of Mackinac.

Over its lifetime, the pipeline has leaked more than 30 times and released more than 1 million gallons of oil. A 2016 University of Michigan study showed that more than 700 miles of Great Lakes shoreline is at risk of being polluted should the pipeline fail in the straits.

Enbridge, the Canadian company that operates the pipeline, has proposed boring a tunnel under the straits to protect the pipeline and continue its operation. The Trump administration, after issuing an executive order that declared a national energy emergency, has instructed the U.S. Army Corps of Engineers to fast-track its environmental impact evaluation of this tunnel proposal.

The Corps of Engineers released its draft Environmental Impact Statement May 30, potentially clearing the way for Enbridge to move forward, following a 30-day public comment period, but not without opposition.

Mike Shriberg, professor of practice at the U-M School for Environment and Sustainability, is available to comment on this contentious project. Shriberg, who is also associate director of the Cooperative Institute for Great Lakes Research, has been working to document the history of the pipeline that’s pitted environmental groups and the state of Michigan against an oil company—and the Canadian government (Shriberg and U-M students created a teaching case about the Line 5 controversy that is available for free online).

Before joining U-M, Shriberg was the Great Lakes regional executive director at the National Wildlife Federation and served on former Michigan Gov. Rick Snyder’s Pipeline Safety Advisory Board.

What makes the pipeline so controversial?

I think Line 5 is an important issue on its own, but what it represents for who has the rights to utilize our natural resources and waterways is critically important, far beyond the specifics of the issue.

The way that I think about Line 5 is, in part, what the overall controversy means in a few different dimensions. One is Indigenous rights. All the tribal governments in Michigan are opposed to the continued operation of Line 5. Some have actually banished Enbridge from their reservations and tribal lands. That’s something that tribal governments take quite seriously and the continuation of Line 5—the building of a pipeline—would be a triumph of corporate rights over Indigenous rights.

Then the state of Michigan revoked Line 5’s easement to operate. Gov. Whitmer did that in 2021. The state of Michigan said Enbridge no longer has a right to operate in the Straits of Mackinac. Enbridge essentially has said, “We don’t recognize the state’s authority on this.” So this is also really important to states’ rights and the ability of Michigan to protect the Great Lakes. It’s hard to imagine higher stakes.

How has Enbridge been countering these actions against the pipeline?

Enbridge’s legal argument to these challenges is, “If you shut this down, you’re going to shut down the U.S. economy.” No judge wants to be responsible for that. To the public, it’s the “freezing granny” strategy. Enbridge is saying, “If you shut down this pipeline, there are people in the U.P. who aren’t going to be able to afford their propane.” But neither of these strategies are borne out by the facts. In fact, whenever Enbridge has to testify under oath, they’ve had to back off those claims and admit that there would be no noticeable economic impacts to a shutdown. But they are still using these scare tactics in the public sphere.

Enbridge Energy has over many years now launched a comprehensive, expensive media and messaging campaign as well as lobbying campaign. They have put untold millions into this marketing and political pressure effort with the explicit goal of changing both public opinion and decision-maker behavior on Line 5.

How does the fast-tracked approval process affect things?

That was part of President Trump’s executive order declaring the energy emergency and directing all agencies to speed up federal projects having to do with energy. The reality is that the U.S. does not have an energy emergency and, even if it did, Line 5 is not a significant contributor to U.S. energy.

Line 5 is an oil and natural gas liquids pipeline that goes from Superior, Wisconsin, to Sarnia, Ontario, using the Great Lakes and Michigan as a shortcut. The oil and natural gas liquids mostly come from Canadian tar sands and are mostly going to Canadian refineries for export. Relatively little is produced or utilized by the U.S.

So the U.S. appears to be fast-tracking a project that’s a benefit to Canadian oil extraction, refining and export. That seems out of line with the stated priorities. The other thing to note is that the Great Lakes Tunnel proposed by Enbridge would also need state permits that it does not have now. It had them, and they expired, so Enbridge needs to reapply. The Army Corps is not the last word on whether this gets approved.

What is Canada’s stance on all this?

Canada has been actively advocating for Line 5 to remain open—in fact, filing briefs in U.S. court on behalf of Enbridge, which is a major economic player in Canada. It’s in Canada’s self-interest to get their oil to markets, and to put the risks of spills on the U.S. I will say now that there are trade tensions, to say the least, between the U.S. and Canada, I think this might put Line 5 in a little bit of a different light.

The U.S. and Michigan, or the Great Lakes region, are taking the risk and getting very little of the benefit. The partnership that the U.S. and Canada have had is fraying right now, and I do think Line 5 is an interesting case of whether the U.S. wants to continue to carry this risk for Canada. So there’s an interesting moment in this controversy, this relationship that I wouldn’t have anticipated six months ago.

When did the controversy start playing out in public?

One of the amazing things about this issue is that it arose in, some sense, from nowhere. It started in 2010, with Enbridge’s oil spill in the Kalamazoo River. A staff member at the National Wildlife Federation—this was before I was there—named Beth Wallace started to raise questions and look at Enbridge’s record and other pipelines in the region. Something that was sparked from somebody asking questions has risen to the highest levels of government concern, something that’s core to the future of our water policy, our Indigenous rights and our energy policy in the U.S.

It’s remarkable and it’s had more twists and turns than a Russian spy novel. It’s gone back and forth so many times. I think advocates have thought they’ve had the pipeline shut down multiple times. I think Enbridge has thought Line 5’s future was secured for a hundred years multiple times.

The debate and the issues keep playing out. It’s one of the more remarkable things I’ve ever been involved with and followed. It’s been a dominant environmental story in Michigan for years. It’s a microcosm of many other bigger battles. It’s important in and of itself, but it’s also important for what it holds.

This Q&A originally appeared on the Michigan News website.