The Yukon's environmental assessment board is considering a mining operation which would bring cyanide heap leaching back to the territory.

Victoria Gold Corp. has been exploring the Dublin Gulch watershed north of Mayo since 2009.

It's proposing to begin development on the property in 2012, with production beginning in 2014.

The proposed project is currently under review by the Yukon Environmental and Socio-economic Assessment Board (YESAB), which is inviting the public to comment on the proposal until Aug. 22.

The last time cyanide heap leaching was used to mine gold in the Yukon was between 1997 and 2001 at Brewery Creek near Dawson City.

Cyanide heap leaching is a way of separating gold from ore by pouring sodium cyanide over crushed ore, which is laid on top of a PVC-lined solution pad.

The gold binds to the cyanide, creating a "pregnant” cyanide molecule, and is then separated using activated carbon.

The technique is often regarded with suspicion – and is outright banned in Wisconsin and the Argentinean province of Rio Negro, as well as all of Hungary.

However, YESAB executive Ken McKinnon said this week he is confident the appropriate safety measures can be put in place.

"Any time you are using a dangerous chemical compound, there are always dangers,” McKinnon said of his initial impressions of the proposal.

"But it has been used safely and we have some good examples to work with here.”

McKinnon said the Brewery Creek site, which had no contamination problems and was touted as an example of how heap leach mining can be done safely at an industry seminar last year, and the Fort Knox mine in Alaska both provide a model of how to safely operate a heap leach operation.

"Eagle Gold is about five times the size (of Brewery Creek), but operating under the same conditions,” McKinnon said. "So we know it can be done in these temperatures.”

Fort Knox, he noted, has had some minor leaks but none which constituted a public health or environmental risk.

The major focus of the assessment will be on safe transportation of the toxic chemical, which comes in briquette form and packed in wooden crates; the quality and quantity of the material used to line the bottom of the ore piles; and the company's water treatment plan, McKinnon said.

"The water they put back into the environment must be absolutely as pure as when they took it out,” he said.

According to Victoria Gold Corp.'s project proposal, the open-pit mine site would take 20 months to prepare, would operate for about seven years, and would take 10 years to reclaim, "followed by a post-closure monitoring phase.”

The company proposes to upgrade the existing road into the property and build a 45-km transmission line to connect to the Yukon's power grid.

"Fuel storage facilities will be constructed to allow for full operation for 30 days without refuelling in the event of an unplanned power failure,” the proposal states.

Although the Dublin Gulch area has been mined for years, the company expects to recover a significant amount of gold from the site.

The company said it plans to move nine million tonnes of ore a year, and take out 170,000 ounces of gold annually, at a cost of $500 per ounce.

According to the Victoria Gold website, the company has identified 4.8 million ounces of gold on the 28-by-15-kilometre site, with another 1.5 million "inferred” ounces.

"I think there was a lot more opposition to Brewery Creek because people didn‘t know if it was a viable way to mine gold in the northern climate,” McKinnon said of the public response he expects to hear.

"... Now I think people are a lot more comfortable with it after seeing Brewery Creek.”

Lewis Rifkind, the mining co-ordinator for the Yukon Conservation Society (YCS), seemed to agree.

"Every time you break up a huge whack of rock and dribble acid on it, things happen. But is it mitigable? Yes,” he said.

He noted that the area "has been heavily worked over,” and there is already some road access to the Eagle Gold site.

The YCS is concerned, however, about the amount of power the mining project would use, and how Yukon Energy would meet the increased demand.

Victoria Gold plans to connect to the existing electrical grid, which already relies on diesel in the winter months.

As Rifkind pointed out, Yukon Energy has a long-term plan (made long before Victoria Gold came to town) to expand the amount of power it can draw from the Mayo hydro plant by raising the water level of Mayo Lake.

If the plan goes forward, this would ultimately affect the surrounding ecosystem, the lake's flora and fauna, and the people who live nearby, Rifkind said.

"Is that part of the Eagle Gold assessment? No, but it is a spin-off,” he said.

And the issue that exists with every mining project is the aftermath, Rifkind said.

"Is this a walk-away project?” he asked. ”... We don't want to end up in another Faro situation where taxpayers are left dealing with water quality and so on.”

The Faro lead-zinc mine closed in 1998 after 29 years of operation.

The company says it has a "conceptual closure and reclamation plan” which would take 10 years, until 2030, followed by a five-year monitoring phase.

In preparing the YCS's comments on the project, Rifkind said he will also look into the potential social impact on Mayo of the 190 people the mine expects to employ.

It is another "mitigable” issue, he said, but he wants to see it acknowledged in Victoria Gold's proposal.

Officials from the company did not return calls from the Star before press time this afternoon.