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Corps readies decision on underwater pipeline supports

The Mackinac Bridge that spans the Straits of Mackinac. The oil-transport company Enbridge said on Wednesday that a gap has opened between a section of its Line 5 pipeline and the staits’ bottom. The company now says it's seeking government permits that will allow it to install screw anchors to provide additional support at that spot and others along the underwater line. (AP Photo/Carlos Osorio, File)

The Mackinac Bridge that spans the Straits of Mackinac. The oil-transport company Enbridge said on Wednesday that a gap has opened between a section of its Line 5 pipeline and the staits’ bottom. The company now says it’s seeking government permits that will allow it to install screw anchors to provide additional support at that spot and others along the underwater line. (AP Photo/Carlos Osorio, File)

TRAVERSE CITY, Mich. (AP) — The U.S. Army Corps of Engineers says it’s preparing to decide whether to let the Canadian oil-transport company Enbridge install supports for its underwater oil pipeline in Michigan’s Straits of Mackinac.

Enbridge disclosed on Wednesday that erosion had opened a gap beneath one of two Line 5 pipelines in the channel, which connects lakes Huron and Michigan. The gap is about 6 feet wider than allowed by a state easement.

The company says the pipe’s integrity isn’t threatened. But it nonetheless wants to install more than 50 screw anchors to provide greater stability.

Michigan has already granted a permit for that work. Enbridge says it has been waiting 16 months for the Army Corps to do likewise.

Lynn Rose, a spokeswoman for the Corps, said on Thursday that the Corps recently received information it needed from Enbridge to make a decision, which will come soon.

Enbridge said the gap between the pipe and the bottom of the Straits of Mackinac poses “no safety or integrity risk” – an assessment that state regulators said they couldn’t immediately confirm. But the Michigan attorney general’s office said the development corroborates the notion that Enbridge should decommission its Line 5, which carries 23 million gallons of oil and natural-gas liquids daily between the cities of Superior and Sarnia, Ontario.

A section of the line, more than 4 miles long, splits into two pipes when crossing the straits. An easement granted by the state when the pipes were laid in 1953 requires that there never be a gap of more than 75 feet between them and the straits’ floor. Enbridge reported to state agencies Wednesday that one such opening had reached 81 feet.

The company said it had applied 16 months ago for a permit to install screw anchors to provide additional support.

“We’re kind of on hold until we get that,” said Ryan Duffy, an Enbridge spokesman. “We have a crew at the straits ready to go. They have the screw anchors and as soon as they get the permit, they can install one in the place that’s been an issue in two days.”

Rose said the Corps sent Enbridge a letter in July relaying concerns that had been raised during a public comment period on the company’s proposed remedy. Rose said the Corps was waiting for Enbridge to respond, although Duffy said the company had already done so.

Environmental groups contend the aging pipeline is becoming ever more prone to leaking. The company, though, says repeated testing and inspections have shown it’s in good shape.

Enbridge officials sat down with former Michigan Gov. Rick Snyder’s administration last year and reached an agreement calling for the pipeline’s current underwater sections to be replaced by a new line enclosed in a tunnel drilled through bedrock beneath the lake bed.

Gov. Gretchen Whitmer, who succeeded Snyder in January, has since demanded that the $500 million tunnel project be built sooner than Enbridge has said is possible. Michigan Attorney General Dana Nessel has separately filed a lawsuit calling for the current pipeline to be shut down.

Enbridge has installed 147 supports in recent years to stabilize the pipes as the straits’ swirling currents have washed sediment from beneath them.

Copyright 2020 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

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