View Point: Water and Oil Don’t Mix – Line 5 & The Straits of Mackinac


By Peter Chow

Last year, Michigan Governor Gretchen Whitmer took decisive action to shut down Line 5 by May of 2021 to protect the Great Lakes from the risk of a catastrophic oil spill in the Straits of Mackinac.

The State of Michigan is revoking and terminating the 1953 easement that Enbridge has relied on to operate its dual Line 5 pipelines in the Straits of Mackinac due to repeated violations of the easement.

This historic action represents a clear victory for the Great Lakes and recognizes that alternatives to Line 5 exist.

Every day, 540,000 barrels, nearly 23 million gallons of oil flow through two aging, corroding pipelines under the Straits of Mackinac, just west of the Mackinac Bridge.

Constructed 67 years ago, during the Eisenhower administration in 1953, well past their planned 30 year expected expiry date, the two 20-inch-in-diameter Line 5 pipelines owned by the Canadian company Enbridge, Inc., lie exposed in the water at the bottom when they cross the Straits of Mackinac.

The 2 pipelines run at depths ranging from 100 – 270 feet.

Enbridge installed concrete support structures under the pipelines in 2010, following the company’s oil spill into the Kalamazoo River in 2010  – the nation’s largest-ever land-based oil spill.

Hundreds of supports elevate 3-miles of the 2 pipelines off the lakebed into the turbulent current.

This design was never approved and makes the pipelines particularly unsafe.

In 2014, it was found that Enbridge was not complying with the spacing requirement for supporting anchors for the pipelines;  anchors should be placed at least every 75 feet.

The pipelines have come off their concrete supports at several spots.

By the end of 2015, eight Michigan counties or municipalities were calling for the shutting down of Line 5 including Cheboygan, Cheboygan County, Emmet County, Genesee County, Mackinaw City, Mentor Township, Munising Township, and Wayne County.

The Kalamazoo River oil spill occurred in 2010.  A pipeline on Line 6 operated by Enbridge burst.

Almost 1 million US gallons of bitumen from the Alberta Tar Sands spilled into the Kalamazoo River.

The heavy bitumen sank to the river bottom, binding with the sediment.

Cleanup took five years.

The oil was initially contained to a 35-mile (56 km) stretch of the Kalamazoo River.

Originally estimated at US$5 million, by 2014, the total cost for the cleanup had risen to $1.21 billion, with an estimated $219 million in costs yet to be paid

Enbridge was forced to dredge miles of the river to remove submerged oil and oil-contaminated sediment.

In July 2016, Enbridge agreed to pay $177 million in a settlement with the U.S. Justice Department and the Environmental Protection Agency – small change to Enbridge, considering the cost of the damage wreaked by their pipeline, merely the cost of doing business.

It was subsequently disclosed that in 2005, Enbridge had learned that this section of pipe was cracked and corroding.

That same 2005 internal report pointed to 1,500 defects in the 40-year-old pipeline.  And Enbridge had decided not to dig up this area to inspect it.

Line 5 had 3 Upper Peninsula spills totalling about 400,000 gallons in 1968.

Line 5 also had a leak of 252,000 gallons near the U.P.’s Iron River in 1972 and a 210,000-gallon leak near Lake Gogebic in 1976.

In 1999 a Line 5 spill at Crystal Falls in the Upper Peninsula from a hairline crack leaked 222,000 gallons of crude oil as well as an unknown quantity of natural gas.

When responders ignited the vapour cloud that formed, it resulted in a 36-hour fire. Five hundred people were forced to evacuate.

Enbridge officials have said that properly maintained pipelines can last indefinitely, but the company’s history of major spills in Michigan and across North America proves otherwise.

Line 5 in Michigan has spilled 33 times discharging at least 1.13 million gallons along its length since 1968.

The pipelines in the Straits of Mackinac cross one of the most ecologically sensitive areas in the world.

The Great Lakes hold 20% of the fresh surface water on the planet.

The pristine Mackinac Straits area supports bountiful fisheries, provides drinking water to tens of millions of people, and anchors a thriving tourism industry with historic and beautiful Mackinac Island right in the center of it all.

A number of troubling factors have come together that cause grave concern:

A vessel anchor strike to Line 5 was the number one threat that consultants identified in their report to the Michigan Pipeline Safety Advisory Board.  The original Bechtel engineers believed that a vessel anchor strike was only “one chance in a million.”

That one chance in a million became real in 2018.

In 2018, an anchor from a tugboat struck the pipeline, leaving 3 deep dents and several deep gouges.  Fortunately, it struck a part of the pipeline resting on the bottom of the strait.  If it had been instead a suspended part of the pipeline, the results would have been horrific.

Then, there is the tarnished safety record of Enbridge, Inc., the Canadian company that operates the pipeline.

There are ongoing issues of compliance with the contract between the pipeline company and the State of Michigan with repeated disclosures of shoddy maintenance, structural flaws in the pipelines and concealment of critical information from state officials that demonstrate that Enbridge is not acting prudently nor completely transparently.

The age, location, and questionable condition of the pipeline.

Highly turbulent currents found within the straits, combined with the corrosive enzymes secreted by zebra mussels, and aging pipe welds and coal tar enamel, increase the risk for corrosion and cracks to occur in the pipes.

Enbridge reports that Line 5 pipeline segments on land near the Straits have lost 26% of their original wall thickness due to corrosion.

The pipeline has come off its underwater concrete supports at several points.

The increase in the volume and pressure of fluids moving through the pipelines.

The lack of transparency about safety inspections and what petroleum products are being transported through Line 5 in the Great Lakes.

Enbridge states that “heavy”, high-sulfur-content diluted bitumen (from the Tar Sands), which is a less refined and more corrosive product, does not currently run through Line 5.  Enbridge said the same thing  before the Kalamazoo spill which discharged 1 million gallons of bitumen in 2010.

University of Michigan scientists have modelled the currents in the Straits of Mackinac and called it “the worst possible place for an oil spill in the Great Lakes.”

A major spill under the Straits of Mackinac would release more than 2.5 million US gallons of crude oil into the hub of the Great Lakes.

Under the best conditions, only 30% of an oil spill would be recovered.

3,528 square miles (15%) of Lake Michigan’s open water and roughly 13,611 square miles (60%) of Lake Huron’s open water would be covered by visible oil.  900 miles of Michigan shoreline would be covered in oil.

The oil spill would inundate Mackinac Island and reach Manitoulin Island.

The spill would contaminate municipal drinking water systems, devastate fisheries, kill endangered wildlife species, reduce coastal property values, and destroy perceptions of the high levels of environmental quality in northern Michigan.

Pollution from a spill would devastate the state’s multi-billion dollar tourism industry.

1.5 million jobs in Michigan are directly tied in some way to the Great Lakes, generating more than $62 billion in wages.

A Michigan State University study estimates $697.5 million in costs for natural resource damages and restoration and more than $5.6 billion in total economic impacts, including:

-$4.8 billion in economic impacts to the tourism economy;
-$61 million in economic impacts to commercial fishing;
-$233 million in economic impacts to municipal water systems;
-Over $485 million in economic impacts to coastal property values.

A major oil spill from the Line 5 pipeline would disrupt Great Lakes shipping and the steel industry around the Great Lakes. Such a disruption would cost at least $45 billion in loss of gross national product in just 15 days.

Due to these issues, the study published by the University of Michigan, in partnership with the National Oceanic and Atmospheric Administration, concluded that Line 5 should be shut down in the Straits of Mackinac.


  1. The lines are 17 years past their life expectancy and are bent, dented, the coating deteriorated and their support undermined by the strong currents. It’s not a matter of if but when this will let go and cause an unimaginable, irreversible underwater oil spill of epic proportions. Just because it is out of sight underwater, it is far from out of mind, and a growing concern by the day.

  2. Like most of us, Dr. Chow never even knew there was a pipeline at the bottom of the Mackinaw Strait until a few years ago.
    Why not?
    Because there was never an issue with the pipeline and still hasn’t been an issue.
    But that doesn’t matter to the eco-numbskulls, and the likes of this writer, who don’t understand that pipelines as the safest form of transportation of oil and other natural energy products.
    I wonder if Dr. Chow thinks electricity comes from the ‘holes in the wall’ as so many others touting making everything become electric seem to think.

    • “Remember, everything is fine until it’s not. You’ll know when it’s not.”

      – “You think so?”

      – “I’m quite sure. If you don’t it doesn’t matter. Nothing will matter then”

      ― Ernest Hemingway, The Garden of Eden

      • Please provide details of the solutions you’re proposing.
        It’s easy to complain, point fingers and cite Google research, even the least trained layperson can do that.
        What takes intelligence and talent is to devise a practical, attainable and sustainable.
        For someone so very opinionated, pretentious and intolerant of anyone else’s opinions like Chow I would expect some suggested solutions.

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