MN DNR, Enbridge Reach Agreement On Moose Lake Aquifer Breach

ST. PAUL, MN — The Minnesota Department of Natural Resources (DNR) has announced an agreement with oil pipeline company Enbridge regarding an aquifer breach at the Moose Lake site.

This breach, located near Swatara in Aitkin County, was connected to the construction of the Line 3 Replacement Project.

Under the terms of the resolution:

• Enbridge will fund $1.2 million in Supplemental Environmental Projects, which the DNR will select to benefit natural resources.
• Additionally, Enbridge will pay $300,000 in civil penalties for violations associated with the aquifer breach.
• The agreement also includes $100,000 from Enbridge for the DNR's ongoing monitoring of the Moose Lake site.
• Enbridge will also provide $1.2 million in financial assurance intended to mitigate any potential future impacts the breach may have on Moose Lake or other natural resources in the area.

The agreement concludes the DNR's enforcement actions related to the Moose Lake site. The department confirmed it will continue to monitor the site and conduct other monitoring as outlined in existing Line 3 Replacement Project permits and site-specific plans.

Enbridge initially reported the upwelling of groundwater at the Moose Lake site in August 2022.

Following an investigation, the DNR determined that a confined aquifer breach had occurred. The groundwater flow from this breach was estimated at 10-15 gallons per minute, which is considerably lower than the 100-300+ gallons per minute observed at three other confirmed breach sites previously investigated by the DNR.

The DNR evaluated several options to manage the groundwater flow in cooperation with Enbridge. Due to the challenging peatland terrain and complex hydrology, the DNR determined it was not feasible to completely stop the flow without causing unacceptable damage to natural resources.

Enbridge performed corrective actions from fall 2022 through 2023 under DNR oversight.

The DNR established long-term monitoring locations and protocols for the site, and funds from this settlement will support this monitoring.

_This article includes AI-assisted reporting. Editors reviewed all content for accuracy.