Creek leaked into defunct Giant Mine: officials

For the second time insix months,Indian and Northern Affairs discovered water from a creek pouring into an old mining pit at Yellowknife's Giant Mine, the department's Ben Nordahn says.

"There's about a five-foot rock wall outside the pit and it was like a waterfall coming into the pit,"Nordahn said in an interview this week.

The federal department is responsible for keeping water out of the old mining shaftsand away from the chambers of poisonous arsenic dust buried under the mine.

When the leak was discovered during a routine inspection in late November,about 150 litres of water per minute was falling into the pit, Nordahn said.

"It was a bad time to happen, but it was a good time to happen, because if it had happened in the springtime it would have been a lot worse," Nordahn said.

Water leaked through dam

The creek water leaked through a makeshift dam of frozen claybuilt during the mine's early days, said Bill Mitchell, the federal official who is in charge of cleanup at the mine site.

A little bit of water is no big deal, he said, but they do try to keep the water from covering the arsenic chambers.

"The arsenic storage chambers are sealed so there's no possibility of the water going into the arsenic storage chambers," he said.

"There is the possibility of the water going into the mine and there's a point where if the flows had increased further then we would have had difficulty maintaining the pumping rates."

Since the leak was discovered, crews have rerouted the creek and fixed the dam until it can be replaced in March, he said.

Meanwhile, the cleanup plan for the abandoned gold mine, which stopped production in 2005 after 50 years in business, has been completed after seven years of work.

The plan is comprehensive and deals not only with the underground arsenic trioxide management "but it also deals with all the surface components, the demolition of contaminated buildings, rehabilitation of contaminated soil areas, tailings covers and a whole host of other things," Mitchell said.

The plan still needs a water licence to go with it before long-term cleanup of the site can begin, a process which could take several years, he said.