Like the root system of some dark, malevolent shrub, over two million kilometres of pipelines pump billions of barrels of oil and gas across the length and breadth of North America every day. The vast majority of Eastern Canada’s oil and gas supply comes from one decrepit, leaky pipeline running through an environmentally sensitive area of the Great Lakes that’s operated by Enbridge, the company responsible for one of North America’s biggest onshore oil spills.

Line 5 is 645 miles long and runs from Wisconsin through the upper peninsula of Michigan and across the Straits of Mackinac, connecting Lake Superior and Lake Huron, to Michigan’s lower peninsula. The 68-year-old line, part of Enbridge’s 27,000 kilometres of pipeline in North America, supplies all of Eastern Canada with up to 540,000 barrels per day of fossil fuel products.


The blue marker above represents the Straits of Mackinac.

If the name of the operator sounds familiar, it’s because in the past decade, Enbridge has been responsible for multiple pipeline spills and leaks without much attention or controversy. The worst one was on Michigan’s Kalamazoo River in 2010. An inquiry conducted after the Kalamazoo spill laid bare the full extent of Enbridge’s embarrassing buffoonery.

The Line 6B pipeline near Marshall, Mich., sent 843,000 gallons of toxic oilsands crude flowing into the Kalamazoo River. In the inquiry by the U.S. National Transportation Safety Board, chairperson Deborah Hersman said: “…you can’t help but think of the Keystone Kops. Why didn’t they recognize what was happening and what took so long?” The report noted Enbridge had a "culture of deviance" on safety matters. But Michigan has yet another Enbridge disaster in the making.

Last November, Michigan Gov. Gretchen Whitmer revoked a 1953 easement that allows Line 5 to cross the environmentally sensitive Straits of Mackinac “based on Enbridge’s persistent and incurable violations of the easement’s terms and conditions.” Enbridge has been typically combative and arrogant, calling the revocation “unlawful” and refusing to turn off the taps, even though leaks in Line 5 have spilled over a million gallons of fuel in the past 50 years.

The easement mandates that to prevent the line from twisting in the straits’ fierce current and compromising the integrity of the pipeline, there must be anchor supports over stretches of pipeline in the lakebed longer than 75 feet. A 2003 survey found “16 unsupported spans greater than 140 feet; the longest at 286 feet.”

On April 1, 2018, a tugboat was towing a barge in heavy seas and dragged its anchor over the pipeline in the Straits of Mackinac. Enbridge called it a 100-year event. Except it was a two-year event. There was another incident shortly afterwards, and in 2020, the Coast Guard found Enbridge’s own contracted vessels were likely causing damage to Line 5. The company got a couple of fast boats to patrol the area to detect anchors awry, bragging about its “much more active approach.”

The energy needs of Eastern Canada largely depend on a leaky old pipeline, writes journalist and author Trevor Greene. #Line5 #cdnpoli

Because the strong currents in the Straits of Mackinac reverse direction every few days, a mighty surge of water equivalent to more than 10 Niagara Falls, a pipeline rupture beneath the channel would quickly contaminate shorelines miles away in both lakes Michigan and Huron. One hydrodynamics expert calls the area the “worst possible place for an oil spill in the Great Lakes.”

So, the energy needs of Eastern Canada largely depend on a leaky old pipeline operated by a careless, irresponsible company with a dismal accident record and lax attitude toward safety protocols and government regulations. It’s long past time on both sides of the border to enforce safety standards, diversify energy suppliers and reduce dependency on fossil fuels.

Trevor Greene is a journalist and bestselling author. His latest book is 'There Is No Planet B: Promise and Peril on Our Warming World.'

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Straits of Mackinac join Lakes Michigan and Huron

As Mr. Greene notes, Michigan has seen a shorter version of this movie before and that one didn't end particularly well.

I'm sure that given the conditions - crazy, strong, reversing currents between two massive bodies of freshwater - that the pipeline must have been overbuilt to have lasted this long. But could it not also be that those same conditions make monitoring for leaks and weaknesses along its 6.4km length a real challenge? And I think it's telling that the proposed replacement solution involves a completely different, much more expensive technology. If the current pipeline is so good, so safe, why not replace it with a clone of exactly the same thing and keep that going for another 50 years? And why not to have started to build that cloned line twenty years ago when the current pipeline was (only) forty years old?

I was just reading up on dilbit and diluent on cepa.com and according to producers it apparently is not more corrosive than conventional oil unless heated to 200C. I bet it stays fairly cold in the Straits. That's probably helped. Still it seems like a crazy risk to take for want of a pipeline. A sixty year old pipeline, that was only designed to last fifty years, running underwater for 6.4km. What could possibly go wrong and what would be the fallout? Would refineries in Sarnia be on the hook for this fallout, too? One suspects that if there was a major spill it would likely mean the end of Enbridge as a company and taxpayers would be burdened to try and cope with the resulting mess and the ongoing legacy of the mess. There would likely be finger pointing and job losses in Sarnia, too.

When the externalized risk is so great that it easily eclipses the value of the company, shouldn't we expect governments step in? If the meantime, haven't we all been underwriting Enbridge every day for the last 10 years and every day going forward that the oil continues to flow? Finally, were it forced closed, does Enbridge even have the wherewithal to safely decommission that stretch of pipeline? Seems like a lot of waterlogged steel to lift and barge section by section by section.

It's easy for producers and consumers of the oil flowing through the pipeline to worry about it being closed, but that's not the point here at all, is it? When these folks say it cannot be closed, aren't they actually saying and admitting that it can? Isn't it really just that they can't afford it to be closed? This seems like a much easier problem to solve.