Enbridge Line 3

Project summary

The U.S. Army Corps of Engineers, St. Paul District, issued an individual permit on Nov. 23, 2020 to Enbridge, Inc., for construction-related impacts to waters of the United States resulting from its Line 3 replacement project.

The authorization includes:

 (1) Construction activities would result in temporary discharges of fill material into 1,049.58 acres of wetlands, 1.13 acres of streambed, and permanent discharges of fill material into 9.97 acres of wetlands. Temporarily-affected wetlands will be restored to pre-construction conditions and mitigation will be provided for all for permanent impacts include permanent changes in wetland type.

 (2) A total of 227 waterbodies will being crossed by the Project, three of which are considered navigable waters; Red River of the North (Mile Post 801.8), Red Lake River (Mile Post 864.3), and the Mississippi River (Mile Post 1069.7). Ditches account for 95 of the waterbodies, many of which are roadside ditches.

 (3) The project crosses the Lost River Flood Control Project, a channel clearing and snagging project, located in Red Lake County, Minnesota

USACE does not regulate the overall construction or operation of pipelines, nor does it regulate the siting of any type of pipeline/utility line or any substance being transported within a pipeline.


The existing Enbridge Line 3 crude oil pipeline was constructed in phases between 1962 and 1968. It is 34 inches in diameter and 1,097 miles long, and extends from Alberta, Canada, to Superior, Wisconsin. It is proposed for replacement due to its age and integrity issues. The section of Line 3 which is the subject of this Section 10/404 application and 408 request includes the replacement of approximately 282 miles of the existing Line 3 pipeline with 330 miles of new 36-inch diameter pipeline and associated facilities from the Red River valve in North Dakota to the Minnesota/Wisconsin border. Enbridge applied for a permit in September 2018. The Corps had its first public comment period on the application in December 2018. Enbridge submitted a revised application in December 2019. A second comment period was held in February 2020.

Project impacts to aquatic resources

Construction of the project in will require crossing 227 water bodies and result in temporary impacts and permanent wetland-type conversions to approximately 1,049.58 acres of wetlands. Approximately 9.97 acres of wetlands will be permanently impacted to construct new above-ground pump stations and valves.

Cultural resources

Beginning in 2015, the Corps of Engineers began working and consulting with interested tribes to gather feedback on the project and identify potential historic properties and cultural resources in the project area. A tribal cultural survey of the project corridor was completed, and elder interviews were conducted. The tribal cultural resource survey (TCRS) of the entire project corridor was completed and elder interviews were conducted in numerous tribal communities. An Avoidance, Minimization, and Implementation Plan (AMIP) was developed to implement the TCRS recommended avoidance, minimization, and protection measures at identified resources of concern to Tribes.  The AMIP also provides all the monitoring plans to include tribal and archaeological monitors, the unanticipated discoveries plan, processes and procedures to be carried out during construction should discoveries occur that would ensure proper treatment and evaluation of resources, for the protection of historic properties and sensitive resources of cultural importance to the Tribes. 

Proposed location 

Enbridge’s designated route generally follows existing utility line corridors across 13 counties in Minnesota and an additional three-quarters mile portion of Pembina County in North Dakota. From the North Dakota/Minnesota border in Kittson County, it follows the existing Line 3 pipeline corridor to the Clearbrook Terminal in Clearwater County. Next, the route turns south from Clearbrook to generally follow an existing third-party crude oil pipeline right-of-way south to Hubbard County. The designated route then turns east to generally follow other existing electric transmission lines until it rejoins the Enbridge Mainline System right-of-way in St. Louis County, through the Fond du Lac Reservation, to the Minnesota/Wisconsin border in Carlton County

Regulatory authority

The Corps has regulatory authority under Section 404 of the Clean Water Act, and Sections 10 and 14 (Section 408) of the Rivers and Harbors Act. The Corps of Engineers does not have control over the entire pipeline and is one of several permitting agencies to review the project; no federal agency has congressional authority to regulate construction of oil pipelines.

The St. Paul District is evaluating the proposed pipeline replacement project to comply with Section 10/404 for work in waters of the U.S. associated with the applicant's designated route, in addition to reviewing a Section 408 request to alter a federal project at the proposed crossing of the Lost River in Red Lake County, Minnesota.

  • The Corps of Engineers regulates any work or structures in, over, or under navigable waters of the United States under Section 10 of the Rivers and Harbors Act of 1899.
  • The Corps of Engineers regulates discharges of dredged or fill material into waters of the United States, including wetlands, under Section 404 of the Clean Water Act.
  • If a proposed pipeline crosses federally-authorized civil works projects, the Corps of Engineers may give permission for any alteration or occupation of certain public works under Section 14 of the Rivers and Harbors Act (33 U.S. Code 408), also referred to as Section 408, when such occupation or use is not injurious to the public interest and will not impair the usefulness of the federally-authorized project.

Click here to view the permit.

Project location

Project overview mapproposed replacement pipeline location 

(click image or here for full-size graphic)

Contact information

U.S. Army Corps of Engineers
St. Paul District, Regulatory Branch
180 5th Street E, Suite 700
Saint Paul, MN 55101

Email: CEMVP-L3R-PN-Comments@usace.army.mil​

Related sites

Minnesota Public Utilities Commission

(calendar, interactive project map, full summary)

(documents to include environmental impact statement)