Yellowknife Bay water no different than upstream sources, mayor says

For part of today, Yellowknife is going to be drawing its drinking water from a place where water was once suspect — Yellowknife Bay.

Bay's arsenic levels below 2 parts per billion, safety threshold is 10 ppb, mayor says

The City of Yellowknife will draw its water from Yellowknife Bay for an hour or two today, as the new water treatment plant is commissioned. The mayor says arsenic levels are well within safe levels. (Jennifer Geens/CBC)

For part of today, Yellowknife is going to be drawing its drinking water from a place where water was once suspect — Yellowknife Bay.

Typically, drinking water comes from the Yellowknife River, upstream of the old gold mines that flank the city. That's been happening since 1968, when the city built an eight-kilometre-long underwater pipe to the river because of concerns about arsenic contamination from the mines.

But the city's mayor says there's no reason for any concern about arsenic levels in the bay.

"We do regular water testing of water that comes from both the Yellowknife River and Yellowknife Bay for things like turbidity but also for things like arsenic," said Heyck. "Through that testing we've found there's virtually no difference between the arsenic levels in the water drawn from the Yellowknife River and the water drawn from Yellowknife Bay."

Heyck says water will be drawn from the Bay for only "about an hour or two" as part of the commissioning of the city's new $30 million water treatment plant.

He says arsenic levels in both the bay and the river are well below two parts per billion. The recommended maximum for safe drinking water is 10 ppb.

In 2010 researchers measured arsenic levels in the lake bed near the bay water intake. The levels ranged from 47,000 ppb to 140,000 ppb.

Heyck says the intake pipe in the bay runs about 30 metres out from the shore and is elevated above the lake bottom.


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