Members of the Tlicho First Nation in Canada’s Northwest Territories have played a significant role in the clean-up effort at Colomac mine, participants in the Northern Latitudes Reclamation Workshop heard in May.
Colomac is a former open pit gold mine that was operated by Washington state-based Royal Oak Mines until 1997. The company went bankrupt shortly afterwards due to the low price of gold and the Canadian government was left with the bill for reclamation, which could be up to C$50 million.
Tlicho families have lived in the Indian Lake area, where the mine is located, for many generations, and they use the land for subsistence activities such as hunting, trapping and fishing.
A combination of traditional and scientific knowledge was used to develop a reclamation plan, George Lafferty, a Tlicho who works for the federal government’s Department of Indian and Northern Affairs, said at the workshop.
The government took a group of Tlicho elders to the mine, found out what issues they were most concerned about, developed remediation goals for each issue, reviewed the scientists’ proposed options with the elders, and determined which options were preferred by the elders, which were acceptable to them, and which were not acceptable to them.
Contoured top of rocks
Remediation goals for the waste rock piles included leaving them physically and chemically stable, promoting and enhancing revegetation and wildlife habitat, improving the appearance of the waste rock piles, and re-establishing the natural drainage between Baton Lake and Steeves Lake, which are outside the three pits.
In the end the government decided against trying to achieve the last goal, because there was too much rock in the area and the process would have cost too much.
During a three-day meeting between the government and the elders, the elders said they preferred the waste rock piles to be contoured on the top and sides, while the government’s preferred option was to contour just the top. This was an acceptable option to the Tlicho.
Completely covering the waste rock piles was also considered, but ruled out because it was too expensive.
“To do nothing was not preferred, because the rock piles, the way they were, at the time, and the way they are now, they’re not safe even for us to walk around,” Lafferty said.
Caribou pathway created
The elders also decided that a pathway for the caribou herd should be created, to keep the animals away from the mine rock area.
Additionally, an 8.5 km-long, 8 ft-high fence was put up around the tailings pond, which contains cyanide, by a mainly Tlicho crew.
“Water management is the biggest problem at Colomac which is being dealt with now, and actually the process is going very well,” Lafferty said.
The cyanide in the tailings pond will be broken down by adding phosphorus, which promotes the growth of algae. The tailings pond was almost ready to overflow before the government intervened.
Once the mine buildings have been checked for hazard contaminants, they will be cleaned up and dismantled.
Remediation of the site is expected to be completed by 2010, and it will be followed by a five-year monitoring period.
