DNR: Line 3 pipeline construction breached aquifer near Moose Lake

State officials say construction work on an oil pipeline in northern Minnesota has again breached an aquifer.

The Minnesota Department of Natural Resources (DNR) confirmed its investigation into the impacts of the breach near Swatara, a remote site around 70 miles northwest of Moose Lake.

It’s the fourth time the Enbridge Line 3 project has resulted in an aquifer breach since October 2021, when the pipeline was put into service, per DNR reports.

According to the agency, the groundwater flow from the latest breach is estimated at 10 to 15 gallons per minute, much less than the past breaches that resulted in flows of at least 100 to 300 gallons per minute.

Enbridge says the breach was caused by sheet metal piling that is used to reinforce the pipeline trench and didn’t involve the pipe itself.

While the department’s investigation is still ongoing, the DNR says it has required Enbridge to come up with a corrective action plan that the agency will then review. Enbridge confirmed it is providing that plan to the DNR and will then implement it once it’s been approved.

In October 2022, the DNR and Minnesota Pollution Control Agency announced results from further investigations into Enbridge’s past aquifer breaches and water quality violations, saying the company would pay more than $11 million and perform environmental restoration work.

In a statement to 5 EYEWITNESS NEWS on Friday, an Enbridge spokesperson noted the Line 3 project modernized infrastructure to improve safety and met “the strictest environmental requirements in state history.”

“The Line 3 Replacement Project was built under the most comprehensive regulatory framework in the history of Minnesota resulting in the issuance of over 60 federal, state, local, and tribal approvals,” the statement said in part. “These approvals included the strictest environmental requirements in state history. Enbridge, with the support of union and tribal contractors, implemented strong environmental safeguards and protections to meet these regulatory requirements and protect natural resources. This included construction oversight by independent environmental agency and tribal cultural monitors with the authority to stop construction at any time. When events were identified, Enbridge reported them transparently and corrected them consistent with plans approved by the agencies.”

The DNR says it will continue to assess all work along the Line 3 corridor as more information is reported.