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Understanding how it works

Life cycle of a pipeline

All aspects of the life cycle of a pipeline – from design and construction to operation and retirement – are guided by our comprehensive Operational Management System and strictly overseen by regulatory agencies and government departments. That's why every TC Energy pipeline is rigorously and precisely built with high-quality materials and the latest proven technology, and monitored by expert staff, every step of the way.

Take the journey with us, and learn about the life cycle of a pipeline from planning to monitoring and beyond.


Planning and approvals

Long before a single shovel of dirt is lifted, a need for energy comes first. Once that's established, a detailed plan is developed that goes through a series of applications and approvals. Here's an overview:


Route selection

One of the most important elements of designing a new pipeline is determining its route. Where possible, TC Energy tries to minimize the route length and use existing pipeline rights-of-way or other previously established corridors, to reduce social and environmental impacts.

Where a new right-of-way must be established, TC Energy works with landowners, stakeholders and Indigenous groups to ensure that valuable information is gathered and incorporated into the final route.


Field work

Our team goes on site to perform detailed studies, conduct surveys and to engineer the overall design.


Community and Indigenous engagement

We meet with local communities early and often to have conversations, gather input and share our plans. We're both proud and committed to the relationships we have with landowners, municipalities and Indigenous groups across North America.


Land and Environmental assessment

We respect the land and the environment. That’s why we always:

  1. Collect and analyze data to understand potential effects of the project
  2. Consider impacts to soil, vegetation, wildlife, cultural and historical resources, current land use, traditional land use and aquatic resources
  3. Develop an environmental protection plan to minimize and mitigate the effects of the project construction



Application and Regulatory Approval

Once we've consolidated feedback and prepared our application, we submit it for regulatory review.

Our regulatory applications contain all the necessary information about a pipeline project – including everything from the proposed route, to the number of municipalities, to the locations of migratory bird habitat and other sensitive habitat or species. It's not unusual for regulators to have specific questions about a project application. When they do, we submit responses and ensure their questions are answered comprehensively.


We only use high-quality materials and the latest proven technology. All stages of our pipeline construction are completed by TC Energy contractors that must meet our strict qualifications and standards.


Temporary workspace

Temporary workspace is required, such as access roads, contractor yards and camps, allowing us to further prepare for the work to come.


Clearing, Grading, Topsoil Stripping

Once surveying is complete, various types of equipment are used to clear the right-of-way. Any measures outlined in the environmental protection plan to protect wildlife and vegetation at this stage are also completed.

A safe working surface is then prepared. This may include preparing the area by stripping and storing the topsoil layer and grading the subsoil, or in some areas where conditions allow, disturbance can be reduced and work can proceed while leaving the surface materials intact.

Our contractors separate and conserve the topsoil removed from the right-of-way, so it can be replaced once construction is complete. Topsoil conservation ensures that equivalent land capability and biological diversity are maintained or reestablished after construction.

Safeguarding Biodiversity | Our Approach


Trenching and Ditching

Crews dig a trench along the right-of-way using backhoes and other specialized machinery. Pipelines are buried underground at a safe depth, adhering to regulatory requirements.


Water Crossing

Safeguarding water is a top priority. Information is gathered about water bodies along the proposed pipeline right-of-way, including studies of the aquatic environment – such as water flow, bank stability, the quantity and quality of fish habitat, wildlife and vegetation. For all water crossings, the ability of ecosystems to recover after construction is carefully considered.

How we protect water



Stringing is the process of placing pre-coated pipe next to the trench.



Depending on the terrain and route of the trench, we may need to bend the pipe with special machines to ensure a precise fit.


Welding, Inspection, Coating

Once the segments of pipe are lined up, welding can begin. Various techniques and technologies ensure our high-quality steel pipe is welded together in one string. Each connection is inspected and must meet strict safety and quality assurance requirements.

Throughout construction, all welds are checked by an X-ray or ultrasonic process to verify each weld is sound and the pipeline is safe.

The surface of the pipeline is coated for protection. Where the pipeline has been welded, a liquid bond epoxy is applied to help protect the weld. After coating, a technique called “jeeping” detects chips or flaws in the coating and, if required, a new coat is applied to the affected area.



The welded pipeline is lowered into the trench with side booms.

A separate crew completes the final welds (tie-ins), connecting continuous lengths of pipeline to the existing system.


Backfilling and Padding

In the final step of construction, the trench is backfilled with the original subsoil and topsoil to cover the pipeline. In some cases, where the terrain is rocky, padding may be needed to protect the pipeline coating.


What happens once the pipes are in the ground, and the earth is moved back into place, filling the trench and covering the pipeline.



Once the trench is backfilled, a series of tests are completed. One key test is called hydrostatic testing, which verifies the pipeline's integrity. Water is placed into the pipeline and pressurized to a level higher than the level the pipe will experience during regular operation. If a leak occurs during testing, we repair or replace the affected section and don't put it into service until it has been tested and deemed safe.


Cathodic Protection

A very low voltage electrical current called cathodic protection is applied to the pipe. The applied current protects the pipe from corrosion. The cathodic protection system is monitored on a regular basis to ensure proper operation.


Clean up and Land Restoration

The final step of construction is to reclaim the right-of-way. Great care is taken to ensure that equivalent land capability and biological diversity are maintained or reestablished after construction.

Reducing our environmental footprint


Our number one priority is your safety. Our goal is to ensure that our pipelines operate safely every day and that the public, our employees and the environment are never negatively affected by an incident involving our assets. Here's how we do it.


Control centres

Our entire pipeline transmission system is monitored 24 hours a day by highly trained TC Energy employees from computerized operation control centres. Satellite technology sends messages to the centre every five seconds to ensure continuous measurement and monitoring of pipeline flow, pressure, temperature and equipment status.

This is one of the many ways TC Energy closely monitors conditions along the pipeline to ensure it is operating safely for the public, our employees and the environment.

Our pipelines are also monitored in other ways, including:
 • Overhead fly-bys by planes
 • On-the-ground inspections
 • 'Smart-pig' inspections,which perform
  micro-inspections inside of our pipelines

In the rare instance of an alert, our system notifies operators so the appropriate response can be taken.


Emergency preparedness and response

We have a top industry record for safe operations; however, we still believe every incident is preventable and continue toward our goal of realizing zero safety incidents. Being prepared for the rare cases when something does go wrong is part of our commitment to ensuring the safety of the communities where we operate.

In the event of an emergency, our goal is to ensure an effective, coordinated response to contain and control any incident to minimize harm to people, property, the environment and company operations.

Learn more about our emergency preparedness planning.


Public safety and awareness

Our pipeline safety programs are among the most robust in the industry. From pipeline integrity initiatives to investing in leak-detection technology and public awareness programs, safety is the common link behind everything we do.


Continual innovation and technology advancements

For over half a century, we’ve been instrumental in testing new technology to maximize pipeline efficiency – from safety improvements to minimizing emissions and more. All to ensure our pipelines – and the communities they serve – are safe.

End of Pipeline Life Cycle

TC Energy’s commitment to managing pipeline assets safely and responsibly throughout the life cycle includes eventual decommissioning or permanent retirement (a process called "abandonment" by regulators) when pipelines and facilities are no longer necessary for service.

For more information on our pipeline End of Life Cycle Program, please visit:

 Natural Gas

 Oil & Liquids