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Enbridge Line 3 pipeline replacement project

Enbridge Energy is continuing restoration work around its new Line 3 crude oil pipeline across Minnesota. The new line replaced an aging Line 3 and began operating in October 2021, after Enbridge completed the project’s construction phase.

In October 2022, Minnesota state agencies and the Fond du Lac Band announced enforcement actions resulting in $11 million from Enbridge in payments, environmental projects, and financial assurances. The MPCA’s portion of this enforcement action addressed Enbridge Energy’s violation of a series of environmental regulations and requirements during the construction of Line 3. The Minnesota Department of Natural Resources finalized two enforcement agreements to address three aquifer breaches related to construction.

More information about the enforcement actions and agreement documents: Enbridge Line 3 enforcement information

Our role

Enbridge needed multiple approvals, permits, and certifications from state agencies, including the Minnesota Pollution Control Agency, to construct the pipeline. Because Enbridge proposed to alter protected wetlands for the Line 3 project by either filling or excavating areas of the wetlands, the company applied for a permit under Section 404 of the federal Clean Water Act (CWA), governing placement of dredged or fill material into wetlands. Section 404 permits are issued by the U.S. Army Corps of Engineers.

The 404 permit requires the applicant to also request a water quality certification from the state under CWA Section 401. This allows the state (in this case the MPCA) to review the proposed activity to determine whether it complies with applicable water quality standards, and to identify any additional conditions needed to ensure compliance.

On Nov. 12, 2020, the MPCA granted final 401 water quality certification for Enbridge’s Line 3 replacement project — the agency’s most stringent water quality certification issued. The certification required Enbridge to take every precaution to safeguard 730 acres of wetlands and more than 200 streams in northern Minnesota. The MPCA reached its final decisions after comprehensive regulatory and technical analysis, extensive public participation, a contested case hearing that investigated the project’s water quality protections, and coordination with other state/federal agencies. On Nov. 23, 2020, the U.S. Army Corps of Engineers issued the federal 404 permit.

During construction and restoration work around the new pipeline, we monitor and enforce environmental regulations and requirements.

Project information

The new Enbridge Line 3 pipeline follows the previous pipeline from North Dakota to the Clearbrook Terminal in Clearwater County, Minnesota. From the Clearbrook Terminal eastward, the pipeline was constructed in a new right-of-way, south of the existing Line 3, ending at an existing terminal in Superior, Wisconsin.

The purpose of the replacement project was to address pipeline integrity and safety concerns related to the previous pipeline and to restore the throughput of the line to its original operating capacity of 760,000 barrels per day.

Next steps and timeline

While the pipeline began operating once construction was completed in 2021, the project remains open as Enbridge works to ensure the site is returned to its condition before construction. The old pipeline, while no longer in use, remains in place. Decisions and permits related to decommissioning the old line will include numerous landowners and require permits from state and federal agencies. The process and its timing has yet to be determined.

The October 2022 stipulation agreement requires Enbridge to fund $2.625 million to complete several supplemental environmental projects in watersheds affected during construction.