Oct 7 2021

Micro-tunneling crosses waterways safely and effectively

Posted by Coastal GasLink

At Coastal GasLinkthe safety of our people, environment and communities is our number one priority. We continually work to find and bring the newest technology to our project and have many tools in our toolbox to safely construct our project, meaning we are always protecting the environment and our highly valued natural resources – such as waterwaysOur 670 km project route crosses many bodies of water and we approach each one with the utmost of care. We undergo testing to collect information about the water bodies along the route so we can make the best decision on how to cross each individual water body. This is no different in our crossing of the Morice River

After completing environmental and technical assessments such as water flow, bank stability, wildlife, vegetation and the quantity and quality of fish habitats, it was determined that a trenchless micro-tunneling crossing would be the safest method for construction to cross the Morice River. Trenchless crossings are proven to allow pipe to be installed under the water body without ever affecting the flow of the river or stream. Currently there are thousands of trenchless crossings throughout BC, operating safely under rivers and streams of all sizes.  

 

Micro-tunneling is one of the most expensive and technically advanced crossing technologies that uses hydraulic jacks and a tunnel boring machine to push concrete casing segments through the soil deep under water bodies in a way that minimizes risk and disposal volume. The pipeline is then safely pulled through the tunnel created by the concrete casing. Micro-tunneling is a remote-controlled excavation method that results in limited environmental, economic, or social disturbances.  

This won’t be the first time that micro-tunneling is used. In fact, it’s regularly used in our communities for public works and infrastructure projects, such as hydro lines, sewer systems and other utilities in BC, and we have support from local and Indigenous communities to use this method at the Morice. Recently, TC Energy utilized micro-tunneling in our Sur-de-Texas project in Mexico. This project holds the world record for the longest micro-tunnel for an offshore-onshore pipeline, and like our other water crossings across the TC Energy footprint, we have had no incidents in construction.  

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Trenchless crossings, like micro-tunneling shown above, allow the pipeline to be installed under the water body.