Skip to main content

What happens if the Line 5 pipeline shuts down?

Mackinac Bridge
Concerns about the environmental impact of Enbridge's Line 5, which crosses the Straits of Mackinac, connecting Lake Superior and Lake Huron, are intensifying. Photo by Brian Rawson-Ketchum / Flickr (CC BY-SA 2.0)

Support strong Canadian climate journalism for 2025

Help us raise $150,000 by December 31. Can we count on your support?
Goal: $150k
$40k

If the battle over the fate of the Line 5 pipeline results in a shutdown this week, the situation could spur a scramble to meet fuel demand in Ontario and Quebec.

Last November, Michigan Gov. Gretchen Whitmer ordered Calgary-based energy company Enbridge to shut down the pipeline, which carries 540,000 barrels of Canadian fossil fuels per day across Wisconsin and Michigan to Sarnia, Ont., by May 12. Whitmer has remained steadfast, even amid a flurry of entreaties from Canadian officials.

It’s unlikely the pipeline will actually go offline Wednesday — Enbridge has so far said it will refuse to comply. But if it were to shut down for more than a few weeks, that could cause a massive disruption, said Warren Mabee, the director of the Institute for Energy and Environmental Policy at Queen’s University.

“It would be chaotic,” Mabee said.

“Over a few weeks, the supply chains can adjust internally, and things can sort of respond. If it goes longer than that, if it looks like it's going to be more of a permanent shutdown, it becomes a much harder logistical piece to deal with.”

It's unlikely that Line 5 will actually go offline this week. But if it were to shut down for more than a few weeks, the situation could spur a scramble to meet fuel demand in Ontario and Quebec, experts say. #cdnpoli #onpoli

Enbridge has taken Michigan to U.S. federal court, and the two sides are currently in mediation. But the next session is scheduled for after the May 12 deadline, and it's unlikely they’ll find a solution in time.

Line 5, which was built in 1953, crosses through the choppy waters of the Straits of Mackinac, a narrow waterway connecting Lake Huron and Lake Michigan. The area is environmentally sensitive, and the twin pipes that make up Line 5 lie exposed on the bed of the channel.

Enbridge has been working on a plan to reroute the aging pipes through a tunnel beneath the bedrock of the straits. The company says the pipeline is safe and has never had a spill, but Whitmer has argued it poses an “unacceptable risk to the Great Lakes, pointing to a 2018 incident where an anchor from a barge dented the pipes, but did not rupture them.

The Anishinabek Nation in Ontario and 12 tribal governments in Michigan have backed Whitmer’s decision.

Line 5 proponents point to the pipeline’s economic impact: it feeds nearly half of Ontario’s demand for fuel, including the jet fuel used at Toronto Pearson International Airport. It also sends fossil fuels to Quebec refineries via the Line 9 pipeline, providing a similar proportion of the province’s supply.

“Line 5 is probably one of the most critical pieces of infrastructure for energy use in Central Canada,” said Aaron Henry, the senior director of natural resources and sustainable growth at the Canadian Chamber of Commerce.

Companies have worked on contingency plans for months, and there’s extra product stockpiled to help weather a few weeks of disruption, Mabee said. Though there are other ways to move fossil fuels should a shutdown go on for much longer, they’re more expensive and logistically difficult.

“There's no natural replacement, there's no other pipe that's empty right now that they could just divert the oil through,” Mabee said. “So you'd be looking at some combination of ship, rail and truck. That’s just going to push your costs up.”

Shipping won’t work in the winter, when portions of the St. Lawrence Seaway are frozen. It might be difficult to find capacity on Canada’s already busy rail lines. Trucks release carbon emissions and cost significantly more.

“It is a tremendous amount of product that suddenly no longer has a very safe, very efficient and very cost-effective method of transporting it,” Henry said.

The Ontario government has said the disruption could cause thousands of layoffs in Sarnia. Those would likely be short-term losses, but if the shutdown went on for years, companies might re-evaluate their business plans and eliminate jobs permanently, Mabee said.

The clash over Line 5 should be a signal for governments to start planning a longer-term transition for refinery workers, Mabee added. Though a sudden shutdown would be tumultuous, the world is moving towards a lower-carbon future that's less reliant on fossil fuels.

“It's not a one-sided story. There is environmental risk associated with the pipeline, and there is long-term environmental damage caused by the oil sector,” he said.

“At the same time, the fact that there's many, many jobs and much of the economy depending on this doesn't necessarily mean it should just be given carte blanche… I think that it's got to be a planned transition.”

Comments