Enbridge oil pipeline construction ruptured an aquifer

Officials with Enbridge Energy and the Minnesota Department of Natural Resources confirmed to the Minneapolis Star Tribune that the breach occurred near Moose Lake in Aitkin County. Officials said Enbridge is working to fix the rupture, in which the layer of earth above an aquifer is punctured, causing the water to leak to the surface and possibly introducing pollutants.

It’s the fourth confirmed breach along the Line 3 pipeline route, which started operating in the fall of 2021 and generated fierce opposition from environmental activists and tribes. Last October, state regulators announced that Enbridge would pay more than $11 million for water quality violations and the three previous aquifer breaches.

An aquifer is a natural underground reserve of fresh water capable of being tapped by wells. Environmentalists say such groundwater reserves face a multitude of threats from human populations, including depletion from overuse, pollution from agriculture and septic systems and contamination from pipeline construction and spills.

Groundwater at the Moose Lake breach is flowing to the surface at about 10 to 15 gallons per minute, department officials said. That’s “considerably lower” than the rate at which groundwater initially flowed from the other three breaks, the agency said.

Enbridge will submit a plan to correct the Moose Lake area damage and will implement it when it’s approved, company spokeswoman Juli Kellner said in a statement. The aquifer breaches don’t involve the pipe itself, she said. It stems from sheet-metal piling driven into the ground used to reinforce the trenches that crews work in.