The Sumas River Crossing Replacement Project is being undertaken in support of Trans Mountain’s integrity and safety program. During routine pipeline inspections of our existing system, an anomaly was identified for repair. To complete the repair, a portion of existing pipe will be replaced beneath the Sumas River.

The replacement involves a combination of a trenchless construction method called Direct Pipe™ and traditional trenched construction. Direct Pipe™ is an installation method that uses a microtunnel to minimize surface disturbance. This method is being used to minimize impact to the surrounding banks and causes no disturbance to the Sumas riverbed. On both sides of the Sumas River, trenched segments will be installed to facilitate tie-ins to the Trans Mountain system. This same approach will also be used to facilitate construction of the Expansion Project in this same area.

To complete the work, a temporary workspace has been set up on the east side of Sumas River to house the drilling rig, associated equipment and stage pipe. A limited temporary workspace and site access is also set up on the west side of Sumas River for retrieval of the direct pipe.

To begin, a casing pipe with a cutterhead attached to the face is pushed into the ground on a pre-determined drill path from the east side of the river, while simultaneously excavating the soil/bedrock by slowly rotating the cutterhead at the face of the microtunnel machine. Once the casing pipe is installed, the replacement pipe is pulled through the casing pipe. The casing pipe is then pulled out while a flowable grout is inserted into the space between.

Trenched construction is then used to install pipe up to where the replacement ties into the existing Trans Mountain system. The entire replacement segment will be hydrostatically tested and examined before it is finally tied into the system.

In accordance with requirements from the Canada Energy Regulator, the now abandoned line beneath Sumas River will be purged clean and filled with grout. Additional portions of the existing line on either side of Sumas River will be removed and the site reclaimed.

Replacement projects like this are an important part of ensuring the continued safe operations of the Trans Mountain pipeline system. Our comprehensive and robust Pipeline Integrity Management Program encompasses a broad spectrum of preventive measures to ensure pipeline soundness and reliability, safety of the public and employees, and protection of the environment.

These preventive measures include continuous 24/7 monitoring of the pipeline, pipeline inspections and investigations, natural hazards management and corrosion protection programs, and damage prevention and public awareness programs. Internal inspection tools, also known as “smart pigs” (pipeline inspection gauges), are used to detect a variety of pipeline defects and form the foundation of our anomaly detection investigation and pipeline repair programs.