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Mackinac Straits Line 5 tunnel plans on course, Enbridge says

Date Posted: March 20 2020

LANSING - The $500 million Great Lakes Tunnel Project under the Straits of Mackinac has completed its geological core sampling phase, is on course for completion in 2024, and will be constructed under a union-only project labor agreement.

That's the word from Anna Mooney, senior government relations strategist for Enbridge Energy, the company footing the bill for the five-mile long utility tunnel which will house the Line 5 petroleum pipeline under the Straits. Mooney spoke on March 3 to delegates of the 61st Legislative Conference of the Michigan Building and Construction Trades Council.

"We are getting into a time that's very exciting, we're still on track with our timeline to complete a tunnel in the Straits in 2024 and tie in the new Line 5," Mooney told delegates. "And we wouldn't be in this position without a lot of your efforts."

Another important bit of news related to the tunnel arrived on March 6, when Enbridge announced that it selected two contractors for the Great Lakes Tunnel Project. One is Michigan-based Great Lakes Tunnel Constructors, a partnership between a Michigan tunnel construction firm, Jay Dee Contractors, Inc., and the U.S. affiliate of Japanese tunnel construction firm, Obayashi Corp.

“We are pleased to be part of the biggest infrastructure project in Michigan,” said Timothy Backers, project manager with the Great Lakes Tunnel Constructors. “We have worked successfully on some of the largest tunnel projects throughout the world, though there is an extra measure of pride in being selected to work on a project where we can make another vital contribution to our home state.”

Enbridge also announced that it has selected Arup, a leading engineering and consulting firm with large-scale infrastructure and tunnel design capabilities, to deliver construction design documentation for the Great Lakes Tunnel Project.

"I also want to highlight our commitment to Michigan jobs and specifically you folks in the room," Mooney said. "We are committed to using Michigan labor when it comes to building this tunnel. For construction and maintenance as well." She affirmed that union trades will work the project. "There will be a PLA," a project labor agreement with organized labor, she told delegates.

The Michigan Building and Construction Trades Council has been a major proponent of the construction of the new utility tunnel under the Straits since it was proposed a few years ago as a safer alternative to the existing dual Line 5 petroleum lines. Since 1953, those 20-inch steel pipelines have been in place atop the bottom of the lake bed in the Straits, part of the 635-mile Line 5 that delivers petroleum products and liquid natural gas from Superior, Wisconsin, across Michigan's Upper Peninsula, across the Straits, then roughly following I-75 in the Lower Peninsula and then crossing under the St. Clair River to a refinery in Sarnia, Ontario. 

Fears of an anchor strike by a vessel on the pipes or some other catastrophic leak, prompted the proposal to construct the tunnel. One of the last pieces of legislation signed into law in late 2018 by outgoing Gov. Rick Snyder was the formation of the Mackinac Straits Corridor Authority, which is a public body that will oversee and regulate the planning, construction and operation of the utility tunnel. 

Environmentalists have pushed Michigan Attorney General Dana Nessel to take legal action to halt the tunnel, but the most recent ruling in January from a state Court of Appeals panel was a 2-1 decision which essentially allowed the construction to continue.

Mooney told delegates that $40 million in geological work on the tunnel ended in November. "A lot of our project was contingent upon really understanding what's in the bedrock under the Straits so that we can build a tunnel," she said. A floating vessel took core samples at least 100 feet below the bedrock of the Straits in an attempt to understand what that special-order boring machine will be cutting into.

Now, she said, "the first thing to come is ordering our state-of-the-art, one-of-a-kind tunnel boring machine."  The new 12-foot diameter tunnel would be bored into bedrock about 100 feet below the Straits, and contain a single-30-inch diameter pipeline, as well as space for other utility runs. Enbridge has said the design will reduce the likelihood of a spill to “virtually zero.”

Enbridge anticipates construction of the Great Lakes Tunnel Project will begin in the fall of 2021. followed by about two years of construction.

Jonathan Byrd, who serves as director of external affairs for the Michigan Laborers’ District Council, introduced Mooney to building trades delegates. He used the opportunity to laud the relationship  between the state's construction unions and Enbridge - and raised hopes for better relationships with Republicans in state government - whose votes, after all, were the primary reason the $500 million project is being undertaken.

"I really want to highlight the amazing partnership the building trades have with Enbridge Energy," Byrd said. "Enbridge has been a partner with us and has helped open a lot of doors with Republicans. We're going to have to change our mindset a little bit, we're going to have to start looking at how do we elect pro-jobs Democrats, and how do we elect pro-labor-Republicans. And they have been really helpful in helping us do that."