Arctic Gold Mine, Nunavut Canada

Nunavut is home to several gold mines, operations that bring significant economic activity to one of the country’s most remote regions. These mines run in extreme cold, with limited road access and short construction windows that make even routine infrastructure work difficult. Any project built at these sites has to withstand freezing temperatures, shifting ice conditions, and a narrow season to get work done.

In July 2025, one of Canada’s most productive mines needed a way to decommission a tailings pond located roughly 11 kilometers away while meeting strict environmental requirements. The plan called for discharging treated water beneath a freshwater cap to create a stable meromictic water body, a solution that required reliable infrastructure capable of performing at depth in frigid conditions.

GreatPacific Consulting Ltd. was brought on to design and install twin 20-inch HDPE discharge lines reaching depths of approximately 80 meters down steep quarry benches. The mine selected GreatPacific after a larger firm determined the scope exceeded its capabilities. A central requirement of the project was completing the installation entirely without divers, a method GreatPacific had used successfully on past Arctic projects.

The team faced a new obstacle at this site. In prior projects, GreatPacific opened valves by using the galvanic series of metals to corrode a structural alloy, a method that only works in saltwater. This pit contained only freshwater, so the team needed another approach. Working with the mine, GreatPacific tested several methods before settling on a custom plug design. HDPE’s flexibility and non-corrosive properties allowed crews to adapt the pipe for unconventional activation methods while maintaining strength and integrity at depth.

Harsh winter conditions initially delayed full deployment, but construction resumed and finished the following summer. The completed lines stretched more than 200 meters and reached depths beyond 80 meters. The successful installation gives the mine a dependable way to discharge tailings while meeting environmental requirements, allowing the nearby tailings pond to move toward decommissioning. It also reinforces how HDPE’s adaptability makes it a dependable choice for infrastructure in some of the most demanding environments in the world.

Image: Adrian Hannam, GreatPacific Consulting Ltd., 2025