Army Corps opens lengthy environmental review of Line 5 tunnel, asks for comment

Beth LeBlanc
The Detroit News

The U.S. Army Corps of Engineers on Monday opened a two-month window for the public to comment on a plan to dig a tunnel beneath the Straits of Mackinac to house Enbridge's controversial Line 5 oil pipeline.

The federal agency's publication of a "notice of intent" of its scoping process allows for public comment through Oct. 14 at

The public comment period is part of the corps' potentially years-long effort to develop an environmental impact statement to determine what the impact of tunnel construction in the straits would be. The corps announced in June 2021 that it would conduct an environmental impact review of the tunnel.  

“Comments should help identify areas for in-depth review, including historic properties, water quality, general environmental effects and other public interest factors," said Lt. Col. Brett Boyle, commander for the corps' Detroit District, in a Monday statement.

"This is a great opportunity to have an impact in the Corps of Engineers scoping process for developing the Draft EIS.”

Enbridge said Monday the start of the scoping process marked an "important milestone" and the company said it was eager to see a draft environmental impact statement.

The state and federal permitting process "is what drives the calendar for the tunnel," said Michael Barnes, a spokesman for the company. "Our sincerest hope is that those who are committed to the tunnel project and Line 5’s long-term safety and environmental protection will collaborate to do this as efficiently and effectively as possible."

Environmental impact statements are prepared to determine what the potential effect is of the project, whether it is "contrary to the overall public interest," or what, if any, special conditions need to be placed on the project when the corps eventually issues a permit. 

It's likely a draft of the environmental impact statement won't be ready until at least fall of 2023 for public comment.

Two other public comment periods between May 15 and July 14, 2020, and Nov. 6 and Dec. 17, 2020, before the corps decided an environmental impact statement was necessary, received more than 15,000 comments. 

The Detroit District in March selected Potomac-Hudson Engineer Inc. out of Maryland to prepare the environmental impact statement, which will be paid for by Enbridge. 

Several tribes and federal agencies will cooperate in developing the environmental impact statement, according to the corps, including Bay Mills Indian Community, Grand Traverse Band of Ottawa and Chippewa Indians, Little River Band of Ottawa Indians, the Sault Ste. Marie Tribe of Chippewa Indians, the U.S. Coast Guard, the U.S. Environmental Protection Agency and the State Historic Preservation Office. 

"... It is extremely important the Corps of Engineers ensure all potential impacts and reasonable alternatives associated with this project are thoroughly analyzed as it will ultimately support the permit application decision,” Boyle said. 

The federal directive comes amid treaty negotiations between the United States and Canada regarding the future of the pipeline as Canada lobbies to keep it operating through tunnel construction, an effort that runs counter to Michigan leaders' efforts to shutter the line. 

Enbridge had requested a construction permit from the corps for the pipeline, but the corps in 2021 insisted on a more in-depth environmental impact statement be prepared first. 

The construction of the roughly 4-mile tunnel between Michigan's Upper and Lower peninsulas was agreed to between Enbridge and outgoing Republican Gov. Rick Snyder in late 2018. At the time, the estimated cost was between $350 million and $500 million to build, and the estimated timeline for construction ranged from seven to 10 years. 

Gov. Gretchen Whitmer and Attorney General Dana Nessel, Democrats who campaigned on promises to close the 69-year-old pipeline, began to negotiate with Enbridge on a shorter timeline when they took office in 2019. But the company said it couldn't meet the governor's two-year timeline. 

Whitmer in November 2020 rescinded Enbridge's 1953 easement in the straits and ordered the pipeline shut down by May 2021. 

Enbridge ignored the shutdown order as the parties fought in court. Michigan lost a key portion of its federal case in November 2021, when a federal judge said the case had to stay in federal court and could not be moved into state court, where the state may get a more favorable ruling. 

The state moved its focus to a separate state suit, which was immediately moved to federal court again by Enbridge. A federal judge has yet to decide whether that case will remain in federal court. 

The November 2021 decision came about a month after Canada formally invoked a 1977 treaty that the country says prevents the U.S. government or Michigan from disrupting the operation of Line 5. 

The U.S. and Canada held negotiations sessions on Dec. 17 and Feb. 25, and a "technical discussion" July 21, according to the U.S. Department of State.

"The discussions were constructive," the department said in a statement Monday. "Both parties recognize that this is a matter of great importance for both countries and our bilateral relationship."