A report given Friday to the State of Michigan from Enbridge concludes that a secure underground corridor for Line 5 beneath the Straits of Mackinac is a feasible replacement alternative to the existing Line 5 crossing.
Mandated in a November 2017 agreement driven by Gov. Rick Snyder, the report is the first of four due to the state this month.
“Line 5 cannot remain in the Straits indefinitely. We need a concrete strategy and timeline to expedite its replacement,” said Gov. Rick Snyder. “This report will help us define a comprehensive solution for all utility crossings.”
The state asked Enbridge to examine three alternatives – a tunnel beneath the Straits, an open cut pipe-in-pipe system, and horizontal directional drilling.
A tunnel would separate Line 5 from the waters of the Great Lakes without disturbing the bottomlands of the Straits, while also providing opportunity for other utilities to be included in the underground corridor.
The report is available online at the Michigan Petroleum Pipelines website.
It is one of four that are part of an ongoing analysis of Line 5 by the Michigan Agency for Energy and the Michigan departments of Environmental Quality and Natural Resources. By June 30, Enbridge, which owns and operates Line 5, also will provide:
Each Enbridge report is being independently reviewed by contractors hired by the state to ensure the accuracy of the company’s information. The reports will supplement independent analyses commissioned by the state to inform a decision on the final disposition of Line 5. That decision is anticipated this fall.
A recent incident in the Straits that damaged utility lines owned by American Transmission Co. — in addition to damaging Line 5 – highlighted safety concerns around all utility lines in the Straits. The state is seeking short-term and long-term measures that will allow for continued connection of Michigan’s peninsulas while reducing to the greatest extent possible the potential for an oil release in the Great Lakes.
In May, the Michigan Department of Natural Resources, with Gov. Snyder’s approval, issued an emergency rule creating a no-anchor zone in the Straits. The emergency rule formalized a previously informal anchor restriction in the Straits of Mackinac by prohibiting anchoring under Michigan state law. Productive discussions are underway with the U.S. Coast Guard on permanent measures that would complement the state’s temporary emergency rule.
The state also is awaiting an independent risk analysis from a team of researchers led by Dr. Guy Meadows of Michigan Technological University.