Yukon says cyanide-contaminated water may have been released at mine cleanup

WHITEHORSE — The Yukon government says it has been informed of an “unauthorized discharge of cyanide-impacted water” at the site of last summer’s mine disaster north of Mayo.

An update from the government says the court-appointed receiver running the cleanup operation at the Eagle Gold mine says a pipe leak was identified on Feb. 17.

The government says the receiver initiated repairs and originally believed the water hadn’t spilled from a lined containment area, so didn’t immediately report it.

Officials now estimate that about 150,000 litres of the contaminated water may have been released into the environment.

The government says water quality data collected at nearby Haggart Creek on Feb. 17 and 18 found elevated cyanide, cobalt, copper and nitrite close to the mine site, but that returned to previous levels within two days, suggesting the cause to be an “isolated incident.”

The mining operation was shut last June and the operator, Victoria Gold Corp., was put into receivership after millions of tonnes of cyanide-contaminated rocks spilled from the heap leach facility at the mine, located about 480 kilometres north of Whitehorse.

The update says despite the short period of elevated contamination, any level of cyanide above guidelines can have harmful effects on fish.

In Wednesday’s statement, the Yukon government says the receiver recently completed construction of a settling pond at the site, which is the final component of the mine water treatment process and “represents a significant milestone.”

“Initial water quality tests on-site indicate that the mine water treatment process is functioning as expected. Further testing is underway this week to confirm that treated water does not exceed licensed limits prior to direct discharge to Haggart Creek,” the statement says.

News of the latest leak comes after government officials said last month that they believe about 19 million litres of cyanide-contaminated water leaked from a containment pond at the site last year before the problem was spotted and the water diluted in early January.

This report by The Canadian Press was first published March 5, 2025.

The Canadian Press