Nov 2 2020

How Coastal GasLink protects the environment when crossing waterways

Posted by Coastal GasLink

At Coastal GasLink, we recognize that water is a highly valued resource and how we navigate water crossings matters to local and Indigenous communities. The project’s 670-kilometre route crosses several bodies of water and we approach each one with the highest environmental and safety standards to prevent adverse impacts on the environment.

“We are held to what I would consider a platinum standard. Health and safety and environment are our two major targets out here. If we fail in those areas, we’ve failed as a whole. So we are here to install this pipeline safely,” says Colby Smith, an Assistant Construction Manager working at the Kitimat River crossing, where pipe was successfully installed this summer.

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The view from above Coastal GasLink's Direct Pipe Install (DPI) site near Kitimat.

Our approach to water body crossings is a multi-faceted process that involves rigorous evaluation of the best available crossing methods to ensure each water body and habitat receives the appropriate protections. Prior to construction at any water crossing, environmental assessments take place including studies of the aquatic environment – such as water flow, bank stability, the quantity and quality of fish habitat, wildlife and vegetation. Information gathered through the assessments, along with regulatory requirements and constructability allows for the selection of the most appropriate pipeline installation method.

Two of the methods Coastal GasLink uses along our route are called Direct Pipe Installation (DPI) and Horizontal Directional Drilling (HDD) which are both forms of trenchless crossings. Other methods include punch or bore crossing and micro-tunneling. Trenchless crossings allow pipe to be installed under the water body without affecting the bed or banks of the river or stream and are used in cases where typical methods are not practical due to constructability, terrain, feature or environment drivers.

HDD uses a specialized drilling rig to bore a path under the water body, progressively enlarging the bore hole until the pipeline is pulled through to the other side. DPI is a recent addition to the trenchless crossing industry and involves both digging the tunnel and installing the pipe at the same time which minimizes disruption to instream activities, the surrounding environment, fish habitat and the riverbank.


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Example of Horizontal Directional Drilling (HDD) going deep beneath the water body.

We recognize the importance of fish and fish habitat to the communities upstream and downstream of where we conduct water crossings. That’s why we have implemented stringent measures such as avoiding disturbance of important habitats during key times, such as spawning areas, constructing when watercourses are dry or frozen as much as we can, and relocating fish downstream from the work site during construction.

During construction, we monitor rivers and streams to make sure our plans are effective. This means monitoring both the stream and the surrounding riverbanks to understand if the measures we’ve put in place to reduce impacts are working, and to determine if changes are needed. If the monitoring shows any unusual results, we’ll address it immediately. This could mean installing erosion/sediment control barriers; temporarily stopping work until the water quality returns to acceptable levels; or re-scheduling work until conditions are more favourable.

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Elise Chow-Stiefvater is a project engineer working on Coastal GasLink at our Kitimat DPI site.

At all of our construction sites, we strive to leave the land the way we found it. As such, our post-construction reclamation and monitoring of waterways includes a variety of assessments to evaluate factors such as erosion sediment controls and surrounding vegetation. By monitoring the rivers and streams after construction, we can ensure safe and reliable operations and monitor mitigation and reclamation progress.

“It’s about doing things safe, with quality and being really proud of it when you’re done. Something you can talk about with your friends and colleagues that we did it right,” says M.J. Zimmerman, Construction Manager.

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Watch to learn more about trenchless crossings and how Coastal GasLink is taking extreme care in crossing rivers and streams.