Both legs of the Line 5 pipeline that carries crude oil and liquid natural gas under the Straits of Mackinac in Michigan, viewed by some as an environmental threat to the Great Lakes, are shut down for now.

State officials are concerned over how Enbridge Inc., the line's Canadian operator, handled a report earlier this month of damage to its east leg. They allege the company failed to provide information about cause of the damage and while it closed that line, it reactivated the west leg without consulting the state.

In response to a restraining order sought by Michigan Attorney General Dana Nessel [D], Ingham County Circuit Court Judge James Jamo ruled June 25 against continued west leg operation and barred restart of the east leg.

The shutdown was to start within 24 hours, and remain in place until a hearing scheduled for June 30 on the state’s request for a preliminary injunction to determine if the two lines are safe. The court also ruled that Enbridge should disclose any information relevant to recent pipeline damage.

The controversy over the 67-year-old pipeline surfaced on June 18 when Enbridge, as part of a maintenance and inspection program, informed the state that an anchor support on the east leg had sustained damage. The support lies about 150 ft from a section of the pipeline that showed damage to its coating that was discovered around May 26.

Nessel praised the court’s ruling.

“Enbridge has failed to provide the state with information about the cause of this significant development involving Line 5, and so I’m very grateful for the court’s decision today,” he said. “While the fact that Enbridge reactivated one of the lines before consulting with the state is concerning, that the company has failed to disclose the cause of this damage is equally alarming, considering the impact a breach in the pipeline could have to our state residents and economy. With the continued operation of this pipeline, the risk of severe and lasting environmental damage to Michigan’s most important natural resource continues to grow every day.”

She called the court ruling a short-term fix, and said the pipeline eventually needs to be shut down permanently and removed. 

“If the lines are put back into operation, one mismanaged incident or accident would result in a historic catastrophe for our state,” she said. “Work must continue toward complete removal of Line 5 from our waters.”  

Enbridge is "disappointed in the court’s ruling," and maintains that Line 5 is safe and is committed to protecting the environment and the Great Lakes while keeping energy flowing, said Vern Yu, an executive vice president.

He said the federal Pipeline and Hazardous Materials Safety Administration has regulatory oversight of pipeline operations and fitness for service, adding that Enbridge will provide the court with information it has requested relating to the agency's approach to assessing the current situation with Line 5, including restart planning for the west leg.

Yu said inspections have determined that the west segment is safe for operations and that the agency has not objected to restarting it,. He said the east leg was shut down pending a review of the damage and assessment of its fitness for service.

Enbridge also contends an extended shutdown of Line 5 would threaten fuel supplies in Michigan and Ohio and result in gasoline supply shortages and cost increases,

Prior to the court’s ruling, Gov. Gretchen Whitmer [D] had sent letters to Enbridge CEO Al Monoco seeking more information about the damaged pipeline and requesting it be shut down immediately until the incident could be investigated and preventative measures put in place.

“The information I have received about this incident leaves many unanswered questions as to the cause of this damage, the catastrophe that may have been narrowly avoided, and the threats that may remain as a result of the damaged infrastructure,” Whitmer wrote. “That’s why I am requesting Enbridge turn over to the State of Michigan all relevant information about this most recent damage and provide affirmative evidence that establishes the integrity of the pipeline.” 

Line 5 is set to be replaced by a utility tunnel under the straits large enough to accommodate trucks for service, a tunnel the Whitmer administration and Nessel challenged in court, but whose legality was affirmed by an appeals court on June 17.

That construction will not begin until at least this fall and is not expected to finish until 2024 at the earliest.