Enbridge Identifies Two Alternatives To Replacing Its Dual Pipelines Under Straits Of Mackinac

Enbridge Energy provided a report to the state of Michigan on Friday that found an underground tunnel would be a possible alternative to replacing its aging Line 5 pipeline. The study is the first of four due out this month.

The 1950s-era pipeline carries up to 540,000 barrels of natural gas and oil per day from Superior to Sarnia, Ontario, Canada. The Enbridge report finds it would be possible to place the aging pipeline within a concrete tunnel or a secondary pipe to reduce or virtually eliminate the risk of a spill.

A third alternative that involved horizontal directional drilling to install Line 5 under the lake bed was withdrawn due to limitations with the geology and drilling equipment.

While alternatives might be feasible, they don’t do enough in the short-term to protect the Great Lakes, according to Mike Shriberg, regional executive director of the National Wildlife Federation’s Great Lakes Regional Center.

“A tunnel may be feasible, but that’s an option that they would estimate would take approximately a decade under a best-case scenario to be put into place,” said Shriberg. “The question before our Great Lakes leaders right now is what will they do today, right now, even for the next 10 years to protect the Great Lakes?”

The state of Michigan has asked Enbridge to study how to reduce the risk of a spill and damage from a potential anchor strike, as well as new technologies that might be used at the Straits crossing.

“Line 5 cannot remain in the Straits indefinitely. We need a concrete strategy and timeline to expedite its replacement,” said Michigan Gov. Rick Snyder in a release. “This report will help us define a comprehensive solution for all utility crossings.”

However, Shriberg argued Michigan leaders should move to revoke the easement for Enbridge, which allows the company to operate its dual pipelines on the lake bed. He added Line 5 should be temporarily shut down because the scope of damage from an April anchor strike is still unknown. Enbridge has said the strike dented Line 5, but it didn’t affect the integrity of the twin pipelines.

Enbridge spokesman Ryan Duffy said in an email the company will be reinforcing the areas that were dented in the next several weeks with a composite sleeve that serves as an extra layer of protection.

In a statement, Enbridge said the company recognizes its responsibility to protect the Great Lakes and meet the region’s energy needs.

“Line 5 has been, and will continue to be, a critical link in the Straits of Mackinac — connecting Michigan’s two peninsulas to safely and reliably deliver the energy Michigan families and businesses rely on each day,” said Enbridge in the statement. “Both feasible alternatives would help ensure the continued safety and protection of the Great Lakes for future generations, and we look forward to our continued collaboration with the state to further explore the viability of these options.”

The reports from Enbridge will be reviewed independently by Michigan-hired contractors. The state has commissioned other studies that will be analyzed. A decision on how Michigan officials plans to move forward with regards to Line 5 is expected in the fall.