Enbridge to begin rock, soil sampling in Straits of Mackinac

Enbridge Inc. said Monday that it is moving ahead with the collection of rock and soil samples in the Straits of Mackinac while it prepares for a court battle with Michigan's governor over a planned oil pipeline tunnel there.

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The Canadian company, which has been drilling into the ground on the south side of the channel that links lakes Huron and Michigan, said it will begin boring into the lakebed this week from a barge in shallow water. A specially equipped vessel based in the North Sea will arrive next month for operations in deeper parts of the straits, spokesman Ryan Duffy said.

The geotechnical work is among preliminary tasks costing $40 million that Enbridge has scheduled for this year as it presses ahead with plans to construct the tunnel in bedrock 100 feet beneath the lakebed. It would house a pipeline to replace dual pipes that stretch across the lakebed and that are part of Line 5, which carries oil between Superior, Wisconsin, and Sarnia, Ontario.

Enbridge received a permit to do the sampling from the Michigan Department of Environmental Quality — since renamed the Department of Environment, Great Lakes and Energy — in January, after signing a deal with former Republican Gov. Rick Snyder last year to build the tunnel.

But in March, state Attorney General Dana Nessel said a law enacted to carry out the deal violated the state constitution. Democratic Gov. Gretchen Whitmer then ordered state agencies to stop carrying out the agreement and began private negotiations with the company on an expedited timetable for completing the tunnel.

Talks broke down earlier this month, with Whitmer pushing to finish the tunnel in two years and Enbridge insisting it couldn't be done before 2024. The company filed a lawsuit with the Michigan Court of Claims seeking a ruling on the legality of its agreement with Snyder.

The Michigan environmental agency told Enbridge last week that it could go ahead with preliminary sampling. The permit allowing that work is "an independent authorization" and remains in effect, said Zach Pohl, a spokesman for Whitmer.

"Based upon the attorney general's opinion, however, the previous agreements authorizing a tunnel are void," Pohl said. "The state has not authorized Enbridge to move forward with constructing a tunnel and any work to achieve that objective is done at the company's own risk."

Enbridge described the geotechnical sampling as "a strong signal of our commitment" to the $500 million tunnel project.