How is a pipeline built?

It takes years to build a pipeline. There are many surveys and studies and plans to be completed to develop a comprehensive plan that addresses societal, developmental, environmental and safety considerations.

Landowners and stakeholders will be engaged in the process

– Numerous environmental studies will be conducted to protect the land, wildlife and water

– Archaeological surveys will help the operator understand and recognize cultural and historically significant sites

– Thorough engineering plans will deliver the best technology for the geography and climate conditions


The pipeline construction process is divided into three phases: pre-construction, construction and post-construction. It’s a highly coordinated, well-planned operation executed by a large team of experienced experts.


Engaging landowners

For months, or even years, before construction begins, teams are in contact with landowners and other stakeholders. Communication continues throughout the construction and post-construction process. Whenever possible, construction is planned to take place when it will create the least disruption for landowners and wildlife.

Surveying and staking

Survey teams travel the pipeline route to stake the right-of-way and temporary workspaces. The right-of-way is the area where the pipeline will be buried and can be up to 40 metres wide.

Preparing the right-of-way

Clearing crews remove vegetation and structures from the right-of-way. In cultivated areas, the topsoil (the top 15 to 25 cm containing the organic material that supports vegetation) is carefully removed and set aside, as it will be returned to the ground after the pipeline is in place. The depth and type of topsoil is identified and recorded during the environmental assessment by the survey crew.

Digging the trench

To minimize the disturbance, machines create a trench precisely the width and depth necessary for the type of pipeline being built. The equipment used to dig the trench varies depending on both the type of soil and trench required.

The trench digging crews move quickly, sometimes covering several kilometres in a day.

Stringing the pipe

Crews mark the center of the trench area and lay out individual lengths of pipe, carefully placing them end-to-end along the right-of-way. The pipe is precisely designed for the conditions it will be exposed to. Every element is focused on maximizing strength and safety, including the type of steel used, the thickness of the pipe and the corrosion-resistant coatings.

pipeline being carefully laid into a trench

The pipe is carefully laid into the trench. Photo courtesy of Trans Mountain.


Welding the pipe

The sections of pipe are welded together, using techniques to make the points where the pipes connect even stronger than the steel in the pipe. Welding shelters are sometimes placed over pipe segments so welders can fuse the segments together while protected from wind or weather.

Every weld is inspected using an X-ray or ultrasound and is 100 per cent certified.

Bending the pipe

A pipe-bending machine may be used to match the contours of the land. It’s a gentle and gradual process that retains the strength and shape of the pipe, but allows the operator to follow the safest, most responsible route.

Coating the pipeline

Special coatings are applied to the pipe during the manufacturing process to prevent corrosion. The coatings are formulated to bond to the molecules in the steel, creating a powerful shield. The protective coatings are precisely designed for the conditions outside the pipeline.

Positioning the pipeline

The welded pipeline is then gently lowered into the prepared foundation of the trench. Bulldozers using cranes called side booms carefully place the pipeline into the prepared trench bed. The side booms are designed to prevent damage to the pipe and its exterior coating.

Installing valves and fittings

At this point, the shutoff valves and remote sensors are installed. The sensors will send information to the master control room on flow rate, pressure and temperature, allowing technicians to closely monitor the line. Valves can quickly shut off the pipeline in case of emergency.

Restoring the site

Once the pipeline is in place in the trench, the soil is returned to the ground in the sequence in which it was removed, and the land is returned to its original shape.

The process – from staking the right-of-way to beginning restoration of the site – can take place in as little as 10 days.

Post construction

Testing under pressure

The pipeline is put through a rigorous series of tests, including pressure testing for a minimum of eight hours using nitrogen, air, water or a mixture of water and methanol. Results are analyzed and shared with the regulator prior to approval to open the line.

Remediating the land

Environmental experts like biologists and agrologists remediate the land with indigenous vegetation. Wildlife experts ensure there have been no long-term impacts to animals. The operator begins a monitoring and remediation period of no less than three years immediately following the completion of initial right-of-way restoration. The three-year period ensures any impacts from construction can be identified and corrected.

Regulating every metre of the pipeline

Strictly regulated over the pipeline’s lifespan, at the either federal or provincial government level, pipelines must follow rules detailing how pipelines will be built, operated and even retired – while always putting the environment and safety as their primary considerations. Pipeline operators follow high standards for pipeline materials and methods that are set by third-party organizations like the Canadian Standards Association (CSA Group).

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