Line 3 Pipeline Replacement Program | The Canadian Encyclopedia


Line 3 Pipeline Replacement Program

The Line 3 Replacement Program (also known as L3RP) is an upgrade to the Enbridge Mainline pipeline. The existing crude oil pipeline runs from Hardisty, Alberta to Superior, Wisconsin. The 1,660 km long upgrade is the largest project in the history of Calgary-based Enbridge. The Alberta to Manitoba section of the L3RP has been in service since December 2019.

Enbridge Line 3 Pipeline Replacement Project


The National Energy Board held hearings on the replacement program in late 2015. In November 2016, the Canadian government approved the project. Proponents such as the United Steelworkers union and Saskatchewan premier Brad Wall welcomed the decision. However, some environmental groups criticized it. They suggested that the Canadian government should instead invest in renewable energy. The Federation of Sovereign Indigenous Nations chief Bobby Cameron urged the need for “stringent protections for the environment.”

The L3RP involves upgrading 34-inch-diameter pipes to 36 inches. It will allow for a daily flow of 760,000 barrels of light, medium and heavy crude oil to two facilities in Wisconsin. The completed Canadian upgrades cost CA$5.3 billion. Upgrades in the United States are expected to cost US$2.9 billion.


Enbridge began construction on 1 August 2017. The Canadian portion of the L3RP has been in service since late 2019.

Construction of the Minnesota portion hit several delays. In June 2019, the Minnesota Court of Appeals ruled that the project’s environmental assessment failed to consider the impact of a potential oil spill in the Lake Superior watershed. On 1 May 2020, the Minnesota Public Utilities Commission found that a revised environmental assessment was adequate.

On 30 November 2020, Enbridge announced that it was starting construction in Minnesota after obtaining the final permit it needed for the L3RP.

Enbridge Line 3 Pipeline
Hardisty, Alberta, 10 August 2017.

Key Terms: Line 3 Pipeline Replacement Program

Crude oil (or petroleum)

Unrefined hydrocarbon oil that is extracted from the earth to process for various human uses.