Enbridge Energy’s 645-mile Line 5 pipeline is part of its Lakehead System, which begins in Superior, Wisconsin, and ends in Sarnia, Canada. Federal approval for the Michigan tunnel, which would be bored into bedrock underwater through the Mackinac Straits, is necessary because the project involves building structure in and discharging materials into U.S. navigable waters.
The company had originally promised to complete the structure next year, and expressed frustration about the further delay.
“While we are supportive of a thorough, comprehensive and carefully considered permitting process that ensures adequate opportunity for review and comment, we are disappointed with the extended timeline for a project of this scope,” Enbridge said in a press release.
Another barrier to the project is a lawsuit brought in June 2019 by Michigan Attorney General Dana Nessel, which seeks to void Enbridge’s use of the 1953 Line 5 easement and end its use of the existing pipelines in the Straits. An earlier 2018 lawsuit has been resolved, according to the state of Michigan.