Two giant storage ponds containing toxic cyanide from the June rock slide at the Eagle mine in the Yukon are nearing capacity owing to the inability to treat water tainted by the catastrophe, raising the risk of yet another spill.
Four million tonnes of cyanide-laced ore collapsed at Victoria Gold Corp.’s outdoor gold-processing facility in late June, causing massive damage to mine infrastructure and contamination. About two million tonnes of contaminated materials broke through the company’s containment zone and spilled into the local environment, killing fish and raising concerns about groundwater pollution.
Victoria Gold was placed into receivership in August with PricewaterhouseCoopers Inc. taking over the cleanup and environmental mitigation effort and the Yukon government providing the funding.
Much of the on-site contamination at Eagle is being stored in two legacy storage ponds, which were not designed to treat heavy levels of cyanide concentration. Prereceivership, Victoria Gold was unable to effectively treat the effluent. In fact, after Victoria Gold discharged water it believed was properly treated, dozens of fish were killed in the vicinity of the mine. PWC has since appointed a new water-treatment firm in the hope that it would be able to solve the water-treatment problem, but so far progress has been slow.
“The ponds are full, they’re nearing capacity,” said Erin Dowd, the technical lead on the Eagle gold response with Yukon’s Department of Energy, Mines and Resources in a news conference on Friday.
Earlier this week, Nicolas Harvey, former manager of engineering and projects at Victoria Gold, told The Globe and Mail that wet weather, which routinely hits that part of the Yukon in October, threatens to overflow the two legacy ponds, which have a combined capacity of 335,000 cubic metres, or 335 million litres.
“Unless you start treating it, it’s going to overflow,” he said.
Ms. Dowd said the operator has been looking at different methods and technologies, but “at this time, we do not have the ability to treat and discharge water.”
As the water-treatment firm scrambles to try to figure out a way to treat the contamination, efforts are under way to increase storage at the site. Over the next 24 hours, new storage coming online should pre-empt the need to discharge water into the environment, Ms. Dowd said.
Eagle is located about 375 kilometres north of Whitehorse and 85 kilometres north of the village of Mayo, on the traditional territory of the First Nation of Na-Cho Nyak Dun. The cost to clean up the contamination and remediate the site has been pegged at up to $150-million by the Yukon government and projected to last into next year.
A major reason why Victoria Gold was placed in receivership was the assertion by the Yukon government that the Toronto-based gold company was not following important orders aimed at addressing the spill. One of those directives was to start the construction of a safety berm on-site, which allows the installation of groundwater monitoring wells. John McConnell, Victoria Gold Corp.’s former chief executive, told The Globe in August that the berm design that the Yukon government had in mind was not safe – an assessment Mr. Harvey, the former company engineering manager, echoed this month.
Lauren Haney, Yukon’s deputy minister of energy, mines and resources, at the Friday news conference disputed the notion that the territory placed unreasonable expectations on Victoria Gold around the berm construction.
“I’m very confident in the excellent engineering team and construction team that’s doing the work right now,” she said. “I would also say at any time Victoria Gold was certainly welcome to have taken the objective and the design parameters provided to it and built on that with their own expertise and make it happen. They chose not to.”
The initial order to start construction on the berm was issued to Victoria Gold in July, but the construction only started a few weeks ago. A major reason for the delay was owing to concerns over finding safe accommodation at the site for workers.