The receiver of a defunct Yukon gold mine that suffered a catastrophic storage site failure in 2024 is suing a Vancouver mining engineering company for its alleged role in the disaster.

PricewaterhouseCoopers says in a civil claim filed in B.C. Supreme Court on June 19 that JDS Energy and Mining Inc. provided construction and engineering services to the mine for years, and allegedly made “critical errors” in the lead up to the failure.

The lawsuit stems from a heap leach pad failure at the Eagle Gold Mine near Mayo, Yukon, on June 24, 2024, where about two million tonnes of cyanide-soaked ore spilled into the local environment, including in fish-bearing water bodies.

PricewaterhouseCoopers says in the lawsuit that JDS provided services to Victoria Gold over more than a decade, including consultation, producing studies and construction management at the Eagle mine linked to the ore storage site.

It alleges that the Vancouver company did not properly consult Victoria Gold on practices such as making sure fluids would properly drain from the site, leading to weak layers within the storage facility that triggered the slide.

No one from JDS was immediately available to comment on the lawsuit and the company has not filed a legal response.

The action says JDS failed to address the risks of year-round ore stacking in a cold climate.

“Earlier feasibility studies had recommended limiting ore stacking to 250 days per year during the warmest nine months of the year to avoid the creation of frozen patches within the heap, and had specified heating of leaching solution and burial of irrigation lines.

“Year-round stacking was subsequently adopted following its endorsement in the 2022 Technical Report, which, as noted above, JDS was involved in preparing,” the lawsuit says.