You don't. That's the conclusion reached by government scientists and contractors who have taken on the challenge of removing the environmental hazard left underground at the now defunct Giant Mine in Yellowknife.

At hearings held July 22-23 by the Mackenzie Valley Environmental Impact Review Board, Yellowknife leaders and members of the public made it clear that the Arctic city wants the major hazard cleaned up and removed from within the city limits.

But Canadian and Northwest Territories scientists and the project's developer said the best option out of numerous alternatives considered is to freeze the arsenic in place using "frozen block technology" and keep it frozen "in perpetuity."

Even if the arsenic were flushed out of the ground, technicians could recover only 99 percent of the arsenic as a sludge that would need to be disposed of somewhere else and 1 percent of the poison would be left behind in the ground and still represent a major hazard, the scientists said.

Members of the public told MVEIRB that any solution considered for dealing with the hazard "must be permanent."

"People don't want to live with this indefinitely," one witness said.

"There is no walk-away solution. Obviously, it would be nice to put this to bed and forget about it. But this site is going to be managed into perpetuity," said developer Bill Mitchell.

"Frozen block technology will protect human health, the environment and prevent the illusion of a ticking time bomb in the backyard," he added.