Line 3 Replacement Program (Canada)

Decommissioning

As part of the Line 3 Replacement Program, the existing Line 3 pipeline will be decommissioned—and Enbridge will be responsible for the decommissioned line forever.

In the Canadian pipeline industry, a line is said to be decommissioned when its operations permanently cease, but its end users along that right-of-way do not see a discontinuance of service. Using a traffic analogy, when one lane of a four-lane highway is closed down, traffic still uses the remaining lanes to travel from city to city.

In advance of the potential decommissioning of a line, engineering and environmental assessments are completed in consultation with landowners. And once the National Energy Board approves a decommission application, the process generally involves:

• Removing the vast majority of crude oil from the pipeline with specially designed cleaning instruments;
• Wiping and cleaning the pipeline, using a combination of cleaning instruments and cleaning solution;
• Physically disconnecting the pipeline and sealing it off from active operational facilities, such as pump stations;
• Segmenting the pipeline, where required, by creating permanent physical barriers inside the pipe (including gate valves and permanent segmentation plugs) to prevent the pipeline from acting as a water conduit.

The process does not end there. Enbridge is committed to monitoring decommissioned lines, just as we do with active lines, in various ways. They include:

• Right-of-way monitoring and maintenance, including depth-of-cover surveys;
• Maintaining cathodic protection;
• Maintaining signage, with appropriate contact information, that identifies a decommissioned line in the right-of-way or corridor;
• Maintaining the line’s profile for Call/Click Before You Dig programs.

Generally speaking, Enbridge leaves a decommissioned line in place to avoid major construction activities, and to reduce the risk of soil stability issues that could compromise the integrity of operating pipelines sharing the right-of-way.

This also means refraining from using the heavy equipment that would be needed to excavate and remove the buried pipeline – and that reduces the risk involved with maintaining the safe operation of those other pipelines.

Click here for an illustrated overview of the decommissioning process.

A more thorough explanation of the L3RP's decommissioning process can be found in our application and Project Description document, which have been filed with the NEB.