By Canadian Press

Yukon disaster one of two ‘most catastrophic’ in heap-leach mining history: expert

Jul 8, 2025 | 2:38 PM

An engineer tasked with reviewing the spill of about two million tonnes of cyanide-soaked ore at a Yukon gold mine says it was one of the two “most catastrophic failures” in the 45-year history of the heap-leaching mining process.

Mark Smith says those disasters last year, the other occurring in Turkey, would “define the next 10 or 20 years for heap-leach practices,” in which minerals are extracted from piles of ore by running liquid chemicals through them.

Smith is a member of the independent review board that examined the disaster at the Eagle Gold Mine in June 2024, when an ore slope failed, leading to the contamination of a local creek and groundwater in central Yukon.

He says the board found several underlying causes, including the poor quality of ore, “over-steepened” slope and rising water table at the facility.

Together, he says those factors led to the large-scale liquefaction of saturated ore that triggered the massive failure in a matter of 10 seconds.

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Smith told a briefing hosted by the Yukon government that he hopes the board’s findings and recommendations will extend beyond the territory, steering the industry toward better practices that lower the risks of failures.

He said the site that had been operated by Victoria Gold Corp. had “almost no surveillance,” something that’s “far too common” at heap-leach facilities.

“We need better surveillance of these facilities across the board.”

Asked if other mining companies had reached out to him after the disaster at the Eagle Gold Mine, Smith said he was receiving calls “as often as daily” in the months that followed.

The mine located about 85 kilometres north of Mayo has not operated since the collapse and Victoria Gold was placed in receivership in August 2024.

The review board makes 50 recommendations in its report released in early July, and Smith said none of them are “particularly expensive.”

“I’m pretty sure that the cost burden that’s now been put on the Yukon taxpayers for the Eagle Gold failure would fund all of our recommendations on every mining project that will ever be proposed in the Yukon,” he said.

“I think cost-wise, it’s nothing in comparison.”

Yukon officials have said the territory is reviewing the board’s report.

This report by The Canadian Press was first published July 8, 2025.

Brenna Owen, The Canadian Press

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