Arsenic waste leaked from container at Giant Mine last summer

Arsenic waste was found to have leaked out of at least one container holding toxic material recovered from the roaster complexat the Giant Mine sitelast summer.

The leak, along with another threesuspectedleaks, wasdiscovered in the summer of 2014. The contractor estimated the spillat about five to 10 litres.

Over the last two summers, about 3,000 metric tonnes of material contaminated with arsenic and asbestosremoved from theroaster complex was sealedindangerous goods-approved bags and stored in shipping containers in the mine's tailings ponds.

Runoff water from the waste storage area is treated at the mine's water treatment plant.

Last June a contractor noticed liquid seeping out of one of the containers. It reported fiveto 10 litres of waste had leaked out of a bag.

On further inspection the company found three other containers had also leaked and suspectedthe leaks had come from up to four bags,but it could not confirm they had leaked without lifting them.

The company says the leaks could have been due tomoisture issuesfrom loading frozen bags covered in snow into the containers, which are in direct sunlight and become hot in the summer.

The bags were from the 2013 season, in which 1,529bags were put into containers. The company says toxic waste was double bagged in the 2014 season, in which about 3,000 bags were put into containers.

Spills of hazardous material less than five litres don't have to be reported, but KevinO'Reillyof Alternatives North says the government should have told the public anyway and tested the leak water for contaminants.

"Arsenic trioxide is highly soluble in water and the waste that's stored in those containers is arsenic waste. Who is to say arsenic hasn't leached into the water or snow in those bags."

No one from Aboriginal Affairs and Northern Development was available for an interview.

The bags will stay in the waste storage area for five to eight years, or until remediationtakes place.