GRAND RAPIDS, Mich. (WOOD) — The Michigan Public Service Commission has voted to reopen the record on Enbridge’s Line 5 tunnel project in the Straits of Mackinac, requesting more specific information from the oil company.

The order, which was approved unanimously, said the current record is “deficient” in the tunnel’s potential for fires and explosions. The commission also has remaining concerns about how construction of the tunnel project could impact the current Line 5 pipelines.

The MPSC did not set a deadline for the added testimony, instead deferring any scheduling to the courts.

Almost all of the public commenters applauded the commission’s decision to request more information, encouraging them to reject the project and get the pipeline out of the Great Lakes.

“Today, your vote for more information really speaks quite loud and clear to Enbridge’s default to obfuscation,” one supporter said. “Of course, you need more information because the tendency is to try to limit what the real effects of this tunnel is and what the real dangers are.”

Enbridge’s plans for the tunnel project have been in the works for years. In his final month in office, Republican Gov. Rick Snyder signed legislation to create the Mackinac Straits Corridor Authority and approved an agreement to allow Enbridge to build its new tunnel and pipeline.

Enbridge’s original timeline planned to start construction in 2021 and have the new pipeline up and running by 2024. However, the project was brought to an immediate halt when Gov. Gretchen Whitmer, a Democrat, took office in early 2019.

Enbridge Pipeline Map_111020

Enbridge touts the tunnel as a safety upgrade. The twin pipelines would be encased in a reinforced concrete tunnel to prevent anchor strikes or other environmental impacts that have hurt the lines in the past.

The tunnel would be buried between 60 and 250 feet below the bed of the Straits. The company claims the environmental risk of a spill within the tunnel is almost nonexistent. Many environmental groups disagree.

“The drilling of this tunnel could very easily cause a Line 5 spill,” Sean McBrearty, the legislative and policy director for Clean Water Action, told News 8 last month. “They are going to be drilling right under an existing pipeline. They have not done the necessary geotechnical studies. The geotech report that (Enbridge does) have shows amounts of methane in the groundwater above trace elements, which are signs of methane pockets. They might encounter well drilling, which has caused major explosions in projects like this before. There’s a lot of different problems with this tunnel proposal that really haven’t been fully examined yet.”

McBrearty also addressed the commission during public comment, applauding its unanimous vote.

“The risks of explosion, safety concerns about operating an oil and gas pipeline in a confined space under the Great Lakes, and the fact of Enbridge’s abysmal safety record including the 2010 Kalamazoo River oil spill all deserves closer scrutiny,” McBrearty said.

Following the vote, an Enbridge spokesperson released a statement to News 8. It reads in part: “We remain committed to the MPSC process and seeing that the Great Lakes Tunnel is built.  It will make a safe pipeline safer, assure long term energy security and reliability, and support Michigan jobs and the economy.”


Line 5 was built in 1953 and is 645 miles long. It starts in Superior, Wisconsin, and winds its way through Michigan’s Upper Peninsula, under the Straits of Mackinac and through Michigan’s lower peninsula before eventually crossing into Sarnia, Canada.

The pipeline carries up to 540,000 barrels of crude oil and natural gas each day.

The line is one 30-inch-diameter pipeline but splits into two 20-inch-diameter lines in the Straits. The pipes used under the Straits are coated with enamel and are nearly a full inch thick, three times as thick as a typical pipeline. Enbridge claims the pipelines were tested to withstand up to four times the pressure it faces as the bottom of the Straits of Mackinac.

The calls to shut down Line 5 have picked up over the last decade, particularly in the wake of the 2010 spill on Line 6B that dumped an estimated 21,000 barrels — 840,000 gallons — of heavy crude oil into the Kalamazoo River and its tributaries.

Several studies show a major leak in the Straits of Mackinac would be devastating for the Great Lakes — which accounts for more than 80% of the freshwater in the United States and roughly 20% of the world’s freshwater supply.

A 2016 study by researchers at the University of Michigan ran simulations of a 25,000-barrel leak in the Straits of Mackinac. The simulations estimate upwards of 720 miles of shoreline along Lake Michigan and Lake Huron would require cleanup. Mackinac and Bois Blanc Islands would be seriously impacted, and other areas like Beaver Island, Harbor Springs and Cheboygan would face serious risks.

“These findings show that under the right conditions, a spill in the Straits of Mackinac could affect a significant amount of shoreline and open-water areas in either Lake Michigan or Lake Huron, or both, very quickly,” U-M hydrodynamics researcher David Schwab said in his report.

Environmental groups like the Michigan League of Conservation Voters and For Love of Water are pushing for the state or federal government to shut down Line 5 and force Enbridge to re-route the pipeline away from the Great Lakes, but the concerns aren’t purely environmental. There are economic concerns, as well.

A study commissioned by For Love of Water estimated a 25,000-barrel spill in the Straits could cost the Great Lakes region up to $6 billion dollars in a matter of weeks following the spill.

Gov. Whitmer revoked the 1953 easement that allowed the Canadian company to run its pipelines through the Straits, but Enbridge defied the order and opted to push the fight to the courts. Whitmer and Michigan Attorney General Dana Nessel, also a Democrat, are hoping to hold the case in a state court, while Enbridge is pushing for a federal hearing.

President Joe Biden has championed green energy and a shift away from fossil fuels but has yet to take any formal action against Enbridge or Canada.