Does Line 5 put Michigan’s Great Lakes at risk for a ‘catastrophic’ oil spill?

4.5 miles of Line 5 runs under the Straits of Mackinac


Watch the full documentary in the video player above and view an interactive version of this article at clickondetroit.com/Line5.


A 4.5 mile stretch of Enbridge Energy’s Line 5 pipeline that runs under the Straits of Mackinac has sparked anger, lawsuits, and serious concerns about the threat it poses to the Great Lakes.

Millions of gallons of oil move around the country unseen. Pipelines were built all over the country as a way to move hazardous liquids instead of using trains, trucks, or ships. So, while pipelines are nothing new -- a 70-year-old section of the Line 5 pipeline makes many people very nervous.

The Line 5 pipeline was built in 1953. It begins in Superior, Wisconsin, extends through Michigan and ends in Sarnia, Canada. When it travels under the Straits of Mackinac it diverges into two, 20-inch-diameter, parallel pipelines for 4.5 miles.

Line 5 transports up to 22.68 million gallons per day of light crude oil, light synthetic crude, and natural gas liquids. The natural gas liquids are refined into propane, and according to Enbridge, Line 5 supplies 65% of propane demand in the Upper Peninsula and 55% of Michigan’s statewide propane needs.

Experts say if the section of Line 5 under the Straits of Mackinac were to rupture, the effect on Michigan’s economy and environment would be catastrophic. Which brings us to another catastrophic oil spill -- the Line 6B rupture of 2010 in Marshall, Michigan.

2010 Marshall oil spill

In July 2010, Enbridge’s Line 6B ruptured in a wetland near Marshall, Michigan sending more than 840,000 gallons of crude oil spewing into the Talmadge Creek and nearly 40 miles down the Kalamazoo River. It is one of the largest inland spills in U.S. history.

Following the spill, federal investigators concluded that Enbridge had not properly maintained the 41-year-old pipeline. The spill brought attention to the potential damage that could occur if the Line 5 pipeline running beneath the Straits of Mackinac were to fail.

Until that disaster, many people didn’t realize just how close the pipeline was to their homes. The spill drove 150 families from Marshall permanently, including Jaynan Montague and her family.

Montague raised her children in Marshall. She said she had lived there for around 35 years, but after the spill, she felt like her life would never be the same -- so she moved her family away.

“I got here and you could smell it, and then I walked over and the creek was black,” Montague said, remembering the oil spill. “I knew it couldn’t be good -- and then there was anger.”

“The very first time I stepped near the river I saw a muskrat desperately trying to clean itself of oil, going back in and out of the oiled river,” Beth Wallace said. “I smelled it several miles away -- the toxic, tar aroma, that just overtook all of the communities that were affected was overwhelming in itself. I mean it made you dizzy, it hurt to breathe.”

Beth Wallace is the Great Lakes Freshwater Campaigns Manager at National Wildlife Federation. After the Line 6B spill, she started doing research on pipeline safety -- and she said she couldn’t believe what she found. She learned about Line 5, a pipeline 20 years older than Line 6B -- and located right under the Straits of Mackinac.

“Line 5 became so much more alarming when we learned for four miles that pipeline is exposed and open for four miles in the Straights of Mackinac in Lake Michigan and Huron and poses a massive spill risk,” Wallace said. “It could be up to 700 miles of shoreline that would be affected from the spill. It would be millions of people potentially losing their homes and their livelihood and having to leave. It would be thousands of businesses leaving the area forever, not to mention the wildlife that would potentially never recover.”

Jamie Stuck is the Tribal Council Chairperson of the Nottawaseppi Huron Band of the Potawatomi. Stuck and other Native Americans lived through the Enbridge oil spill in Marshall. Because of what he experienced with the Marshall spill and how Enbridge responded, Stuck wants Line 5 shut down.

“A lot of the tribes within the state of Michigan came here for the fact that you have the largest bodies of fresh water, not only for transportation, commerce, but for sustainability,” stuck said. “The Kalamazoo River is our aboriginal territory for harvesting wild rice, fishing, hunting, transportation, a lot of our neighbors were impacted like you said -- a lot of people had to leave just because of the smell and because of the contamination of their riverfront. Something that is going to take generations to get back to normal.”

Tribes have sent letters to President Joe Biden, asking him to decommission Line 5. Biden has not taken an official stance on the issue.

Line 5 and the Straits of Mackinac

The Great Lakes make up 20% of the world’s fresh water. Two of the Great Lakes -- Lake Michigan and Lake Huron -- meet in the Straits of Mackinac. Line 5 runs right through that area for 4.5 miles.

“The straights are a unique place where the currents between Lake Michigan and Lake Huron can be flowing in either direction. At any given time. Water can be going from Lake Huron into Lake Michigan -- or Lake Michigan into Lake Huron. And it changes direction every two or three days, depending on what the weather’s been for the last two or three days,” retired NOAA scientist Dr. David Schwab said.

Schwab is an oceanographer who studies the Great Lakes. He started using models developed for predicting currents in the Great Lakes to determine what would happen if there were a Line 5 oil spill in the Straits of Mackinac. Schwab said because of the unpredictability of the currents, and the amount of shoreline that could be impacted, the Straits are a very dangerous place for an oil spill. Something everyone in Michigan should care about.

“I couldn’t find a worse place in the Great Lakes to have an oil spill in terms of how far, how fast, and how unpredictably it would spread,” Schwab said. “The people in the Detroit area are citizens of Michigan and one of the biggest assets that we have in the state of Michigan is the fresh water from the Great Lakes. They should be concerned.”

Legal challenges

Michigan Gov. Gretchen Whitmer and Attorney General Dana Nessel have both publicly stated that they oppose the continued operation of Line 5 within the Straits of Mackinac. Line 5 was never supposed to run past 45 years and it has already been in operation for 70 years. In 2020, the state filed a legal order to shut down Line 5. Enbridge refused and the case moved from state court to federal court.

“Most importantly, Enbridge has imposed on the people of Michigan an unacceptable risk of a catastrophic oil spill in the Great Lakes that could devastate our economy and way of life. That’s why we’re taking action now, and why I will continue to hold accountable anyone who threatens our Great Lakes and fresh water,” Whitmer said in a 2020 press release.

In October 2023, Nessel filed in the federal court of appeals asking for an emergency shutdown of Line 5. A decision has not yet been made.

Enbridge argues the pipeline should continue operation because not only does it supply much of western Canada’s crude oil, Enbridge claims Line 5 also meets 65% of the propane demand in Michigan’s upper peninsula. Enbridge wants to keep the oil flowing and has a plan to build a protective tunnel under the Straits of Mackinac to enclose the pipe.

After the devastating Line 6B disaster in Marshall, Duffy said Enbridge has been working hard to rebuild the public’s trust.

“We understand the concerns. And, you know, as far as protecting the waters, protecting the straits, in the Great Lakes, that’s something we very much feel strongly about and believe in,” Enbridge spokesperson Ryan Duffy said.

The company built a $50 million facility after the Marshall spill to use new technology to watch over Line 5. Enbridge monitors boat traffic that travels through the Straits and over Line 5.


About the Authors

Karen Drew is the anchor of Local 4 News First at 4, weekdays at 4 p.m. and 5:30 p.m. She is also an award-winning investigative reporter.

Kayla is a Web Producer for ClickOnDetroit. Before she joined the team in 2018 she worked at WILX in Lansing as a digital producer.

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