Manitoba is the first of four segments in the decommissioning of the old line

By David Coll

As the last leg of Enbridge’s 1,660-kilometre Line 3 replacement pipeline (L3RP) is laid in the ground in Minnesota, decommissioning of the old Line 3 has begun in Canada.

Decommissioning of the 1,097-km Canadian portion of Line 3 has been divided into four segments and will occur in stages, the first of which is underway as of June in Southern Manitoba. The remaining segments (Hardisty to Kerrobert; Kerrobert to Regina; and Regina to Cromer) are scheduled to begin next spring and be complete by the end of 2022.

A decommissioned pipeline is lator (CER) as one that is taken out of service safely and permanently while other existing or new pipelines in the same right-of-way continue to provide service to end users.

“We always approach these projects from the point of view that we are guests on the land.”

— Allen Sawatzky, construction manager, Enbridge

“Leaving Line 3 in place avoids the added disturbance and significant construction activities that excavation and removal would bring,” explains Brett Fixsen, supervisor, projects with Enbridge. “It reduces the risk of soil and slope instability as well as settlement and compaction issues that could compromise the safety of active pipelines sharing that right-of-way.”

Decommissioning work in Manitoba began in early June and covers approximately 260 km from Cromer to Gretna, where Line 3 connects to its U.S. segment. It’s the last step in Canada of the L3RP, Enbridge’s largest ever capital project.

The first step of decommissioning involves scrubbing clean the inside of the pipeline. For this purpose, a pig  trap (a 'pig' is a special instrument launched inside a pipeline for cleaning and general maintenance) is being installed at a site near Enbridge’s Cromer Terminal, south of Virden. Staging for the installation will take a couple of weeks and the cleaning itself about one week.

This part of the process is expected to be complete by the beginning of August, at which time the primary tasks of decommissioning will begin with crews of seven to 10 persons and a peak workforce of approximately 35 contract personnel.

“We always approach these projects from the point of view that we are guests on the land,” says Allen Sawatzky, construction manager with Enbridge. “Our workforce is expected to demonstrate respect and integrity in their personal conduct through all stages of construction – on and off the right-of-way. This includes everything from strictly following public health restrictions and Enbridge’s COVID-19 Safe Work Protocol, to driving courteously and safely on all roads, especially with wildlife, changing weather conditions, large farming equipment and narrow surfaces.”

From August to October, decommissioning will focus on isolating Line 3 from operating facilities (valves are permanently closed and disabled; above-ground features are removed at stand-alone sites); segmenting (small sections of pipe are removed and plates installed to prevent water flow through the pipe); and rail fill (the line is filled with an engineered material at railway crossings to protect rail infrastructure).

“Our commitments to landowners and communities are the same with decommissioning as with construction of the replacement pipeline,” Sawatzky concludes. “That is to return the land to its pre-construction state or better when our work is done.”

The Line 3 Decommissioning Process

The pipeline will be safely removed from service by taking the following steps. Enbridge remains responsible for its pipelines, whether or not those pipelines are active.

1 Removing the oil from the pipeline segment by launching an internal device called a ‘pig.’ Using this method, the vast majority of the crude oil is removed from the pipeline segment.

2 Flushing the pipeline with cleaning agents and cleaning devices (scraper pig) to ensure the crude oil is completely removed.

3 Physically disconnecting the pipeline segment being replaced from any operating facilities.

4 Injecting inert material at certain locations.

5 Monitoring the decommissioned segment of pipe and maintaining the cathodic protection to prevent corrosion.

If a landowner suspects a problem on either an active or decommissioned line, they are urged to contact the Enbridge 24-hour toll free number (1-877-420-8800).

Published in PIPELINE OBSERVER Summer 2021