A U.S. environmental review is expected to delay construction of the proposed Straits of Mackinac tunnel for Enbridge Inc.’s Line 5, the 540,000 b/d oil pipeline that serves Central Canada and the Midwest

Line 5

The U.S. Army Corps of Engineers will require a formal environmental impact statement (EIS) for the Line 5 project, said Acting Assistant Secretary Jaime Pinkham of the Army for Civil Works. 

The Corps “received thousands of public comments and tribal input on the proposed project which warrant further review through an EIS including potential impacts to navigation.” The EIS “will ensure all potential impacts and reasonable alternatives associated with this project are thoroughly analyzed and will ultimately support a decision on the permit application.”

The $500 million tunnel project, created by an agreement with a former Michigan governor but opposed by current Gov. Gretchen Whitmer, already faced environmental review by the state’s Public Service Commission.

The decision to require the EIS instead of a less thorough environmental assessment (EA) “will lead to a delay in the start of construction,” said Enbridge. The Calgary pipeline and utility conglomerate did not predict how long the delay could be.

The delay could add years to the approval process, said supporters of Whitmer’s campaign to close Line 5 as an environmental hazard. She was elected in 2018 in part by pledging to eliminate the crossing.

The governor had ordered construction for the four-mile crossing to be shut down in mid-May after revoking the 68-year-old state property easement between Lake Michigan and Lake Huron. However, Enbridge has prevailed in previous court battles.

“We must ensure the Great Lakes and our communities are protected and a comprehensive review of this project by the U.S. Army Corps of Engineers is a required step in holding Enbridge accountable for the proposal’s impact to our water, land and climate,” said the National Wildlife Federation.