No cyanide risk to drinking water after Victoria Gold accident, Yukon government says

Drinking water is safe to consume after the heap leach pad (HLP) accident last week at Victoria Gold’s (TSXV: GCX) Eagle mine in Yukon, a health official said Thursday, but the company has defaulted on repaying debt.

Dr. Sudit Ranade, Yukon’s Chief Medical Officer of Health made the comment during a news briefing after the results of water samples taken after the accident on June 24 were received this week from a laboratory in British Columbia.

“It’s very reassuring that the water samples that have come back from the regulated drinking water system show no concern, and that is also backed by the watershed analysis that’s been done by the Department of Environment,” Ranade said.

Operations were suspended at Eagle, Yukon’s only producing gold mine after the company reported that a failure at its HLP caused an accident and spill that damaged infrastructure. Victoria shares plunged 84% last week, now valuing the company at $64.3 million. The mine is about 375 km north of Whitehorse.

Video by Blair McBride, The Northern Miner

However, Ranade said people should avoid recreational water use in the immediate vicinity of Haggart Creek near the mine as a precaution. Results there showed elevated levels of cyanide at 0.04 mg per litre, John Streicker, Yukon’s minister of energy, mines and resources said at the briefing.

“This level of cyanide in Haggart Creek could potentially affect fish,” he said. “Whether it will actually affect fish depends on other chemicals in the water. Water sampling is ongoing and fish toxicity testing is underway.”

The cyanide limit for the water quality objective is 5 parts per billion, or 0.005 mg per litre of the chemical, used in heap leach operations to separate gold from ore.

The level is higher at the bottom of the landslide at Eagle, where samples registered 8.58 mg per litre.

Default, injuries, charges

In a Thursday statement, its first news release since the initial accident announcement, Victoria said it had received notices of default from its lenders under a credit agreement from Dec. 18, 2020, without providing further detail. Its first quarter financial report this year states its debt payments total $232.5 million as of March 31. Victoria hasn’t responded to multiple requests for comment.

The collapsed heap leach and landslide at the Eagle mine site. Credit: Yukon government

The Yukon government said in its briefing last Friday that one person was injured in the accident, with two people requiring first aid treatment. The Northern Miner has asked for clarification after the government said Thursday there were no injuries.

The company doesn’t face immediate charges from the accident last week, rather it faces charges related to allegations of water management at Eagle between October 2022 and October 2023, Will Tewnion, compliance director with the department said Thursday, clarifying a comment he made last Friday.

Victoria’s guidance for Eagle this year was to be between 165,000 and 185,000 oz. gold, CEO John McConnell told The Northern Miner during a site visit last week before the accident. But its production and cost guidance forecasts are now retracted, the company said Thursday.

Indigenous cooperation

When the results at Haggart Creek were known, the government shared that information with the First Nation of Na-Cho Nyäk Dun (FNNND), Streicker said. The mine site sits on the traditional territory of the First Nation.

FNNND demanded in a statement posted on Facebook on Wednesday the immediate halt of all mining activity in its traditional territory and an independent investigation and review after the mine accident.

Asked if the government would commit to that halt, Streicker said the question about halting mining is a big one, but added that he doesn’t believe the First Nation wants to end its cooperation on environmental remediation at the site.

Victoria results differ

Government water sample results stand in stark contrast with Victoria Gold’s comments on cyanide.

“Continued environmental surface water quality sampling at multiple points downstream of the property has not detected any cyanide,” the company said in its statement on Thursday.

Asked to comment on that discrepancy, Streicker said experts told the government that a lot of sampling over time is needed over different locations, adding that wildfires have interrupted efforts at water testing.

“It’s like Covid. There can be some false negatives and false positives. As we get more info we’ll get a clearer picture. If a sample says ‘no cyanide’, it doesn’t mean the risk is gone,” he said.

Risk has passed?

But it’s possible the cyanide risk to human health has already passed, Robert Raponi, an independent metallurgical consultant specializing in gold metallurgy and recovery told The Northern Miner in an interview.

Using the 1-gram-per-litre cyanide concentration in a heap leach as an example, Raponi said that would kill fish. But humans would have to drink large amounts of that concentration to experience any effect.

“It either kills you right away or it doesn’t,” he said. “If nothing’s happened by now, unless there’s further slumpage from the stacked ore, it should be pretty much over. The important thing is to shut off the source and it’ll dissipate over time. In warm weather and in sunlight, cyanide will degrade quickly on its own.”

Effects on groundwater, which move slower than rivers and streams will require more sampling, he said.

Scale of accident

The HLP accident caused a landslide 1.5 km in length, involving 4 million tonnes of material, with 2 million tonnes leaving containment, Kelly Constable, director of mineral resources with the Department of Energy, Mines and Resources, said in the Thursday briefing. The heap leach pad can hold up to 90 million tonnes of ore, according to a Victoria Gold technical report.

The company reduced on-site staff to 60 essential workers, while water treatment activities and the pumping of water into storage ponds is ongoing.

The cause of the accident is still not known, Constable said.

Estimates suggest that between 280,000 and 300,000 cubic metres of cyanide-containing solution left the containment, according to Mark Smith, a geotechnical engineer at the briefing.

“The ore on the heap has about 14% moisture, based on Victoria Gold experts,” he said. “Fourteen percent of 2 million is (about) 300,000 cubic metres. Some of that has flowed into the underlying placer tailings. So, the current solution content in that material will be something between 8% and 14%.”

Smith added that risk remains of a secondary failure at the leach pad because of summer rains, though they’re not likely to cause another landslide.