Enbridge Inc. served notice Tuesday that Canadian oil would continue to flow across the Straits of Mackinac regardless of an order by Michigan’s executive branch to shut down the 540,000 b/d Line 5 in mid-May.

Gov. Gretchen Whitmer and Attorney General Dana Nessel have no power to enforce their notice issued in November that the pipeline be evicted as of May by erasing the Straits easement that enabled its construction 67 years ago, said the Calgary-based firm.

“The state lacks the authority to terminate or revoke the 1953 easement,” stated a letter from Enbridge Vice President Vern Yu to Whitmer and Daniel Eichinger, executive division director of the Michigan Department of Natural Resources.

Enbridge in November vowed “a thorough response through the legal process” against the lawsuit by the Michigan executive branch to revoke the state easement for its Line 5 oil conduit.

Yu wrote that terminating or revoking the easement was contrary to the U.S. Pipeline Safety Act and its assignment of policing long-distance conduits to the Pipeline and Hazardous Materials Safety Administration (PHMSA).

Oil flows are to continue while an Enbridge lawsuit seeks to uphold its legal position, and as the Michigan Public Service Commission (MPSC) reviews a $500 million plan to tuck away the contested pipe in a new utility tunnel, said Yu.

“We intend to operate the dual lines until the replacement pipeline under the Straits within the Great Lakes Tunnel is placed into service, as per our existing agreement with the State of Michigan and consistent with PHMSA federal regulatory requirements,” he wrote.

Yu said the Michigan Circuit Court allowed the dual pipe system to resume flowing last September after an 11-week review by PHMSA. The review found no leak threat from damage to an underwater support that prompted Whitmer and Nessel to sue to shut down Line 5.

Yu wrote that the eviction order “ignores scientific evidence, and is based on inaccurate and outdated information. As a result, the notice repeatedly fails to acknowledge that our dual lines in the Straits are safe and in full compliance with the federal pipeline safety standards that govern them, have been found fit to operate by PHMSA, and that no basis for termination or revocation of the easement exists.”

Yu wrote, “Regrettably since January of 2019 the state has consistently refused opportunities to convene discussions on technical issues with Enbridge.” 

He called for meetings of pipeline, state and federal representatives to resolve disputes over Line 5.

The regulatory battle began soon after Democrats Whitmer and Nessel were elected in 2018 on a platform that pledged to eliminate Line 5 as a pollution menace.