Committee to set standard for Yellowknife
Richard Gleeson
Northern News Services
Yellowknife (Jan 24/01) - One thing is a given: the standard for arsenic concentrations in soils in and around Yellowknife will be higher than the nationally established guideline.
Determining how much higher is the work of the arsenic soils remediation committee, composed of federal, territorial, mining and aboriginal representatives.
The Canadian Council of Ministers of the Environment established 12 parts per million as a guideline limit for arsenic in soils.
"Our background (natural level) is higher than that," said Steve Harbicht, head of assessment and monitoring for Environment Canada's Northern division.
The committee is relying heavily on arsenic research by the Royal Military College of Canada in Kingston, Ontario. The college has been studying arsenic contamination in the Yellowknife area.
Ken Reimer, a professor and the college and director of its environmental sciences group, said the most recent research indicates background levels in Yellowknife may be higher than anticipated in a 1999 study.
"We've filled in some gaps in sampling and the indication is the background level for the geological substrate could be up to 150 parts per million," Reimer said.
Arsenic concentrations in Yellowknife soils vary dramatically within the city, from extreme concentrations on mine properties to single digit levels on school grounds and playgrounds.
Reimer emphasized the health hazard presented by arsenic in soils depends on the form as well as the amount of arsenic in the soil.
A series of RMC reports to be released over the next 6-7 months will look at the movement of arsenic through the food chain, differentiating between the various types of arsenic (speciation) and chemical modelling to examine absorption of arsenic in the human digestive tract.
A standard for arsenic contamination in Yellowknife soils will be developed by mid-summer, Harbicht said. The process of developing the standard will involve the public, he said.
Harbicht agreed the standard could have a big impact on the cost of reclaiming old gold mines in the city.
Mine reclamation is also what is driving the development of a regional standard. Reclamation plans are being developed for the city's two gold mines.
"One should spend money and effort where there is genuine risk," Reimer said.
The cleanup of Giant is already under way. The clean-up became a federal responsibility when former owner Royal Oak went bankrupt.
Estimated cost of the surface cleanup at Giant is $16.3 million.
