Ottawa left with bill for northern cleanup

Abandoned mines in Canada’s far north are polluting the tundra, and fixing the problem could cost the federal government $640 million, according to federal documents.

One of the largest environmental threats comes from the abandoned Terra silver mine in the Northwest Territories. The mine is contaminated by polychlorinated biphenyls (PCBs), lead and mercury, according to the documents obtained by Ottawa researcher Ken Rubin from the Department of Indian and Northern Affairs. The mine is on a river that feeds into Great Bear Lake, the eighth-largest lake in the world and the largest in Canada.

In the previous decade, there have been about a dozen high-profile cases of mining companies declaring bankruptcy and leaving behind cleanup liabilities. The documents outline the federal government’s internal assessment of pollution problems faced at these abandoned sites.

Regulations do not require companies to set aside the full cost of cleanups when they close their mines. This leaves the federal government on the hook when companies declare bankruptcy and are unable to decommission their sites.

In the early 1990s at Great Bear Lake, the owners of the former Terra mine declared bankruptcy, and responsibility for the site reverted to the federal government. None of the five individual mines that operated in the area has been decommissioned to federal standards.

The documents say Great Bear Lake is threatened by two other abandoned mines: Contact Lake, a former uranium and silver operation that has not been in production since 1980, and Port Radium, abandoned in 1982. There are 1.5 million tonnes of uranium and silver tailings deposited on the shores of Great Bear Lake. Contaminants include surface gamma radiation, radioactive dust, uranium, arsenic and mercury.