Iqaluit to build bypass at water treatment plant

Iqaluit city council voted to build a bypass around the contaminated ground tanks at the water treatment plant Monday.

It hopes the move will bring it one step closer to restoring drinkable tap water to residents.

Iqaluit has been under a do-not-consume order for the tap water since Oct. 12 when city staff discovered a strong fuel smell in one of its two wells at the water treatment plant.

However, during a presentation at a special city council meeting Monday night, the city heard from the hired engineer firm thatthe entry point of the hydro-carbon contamination was near the beginning of the water treatment process at the raw water storage tank.

The city's chief administrative officer, Amy Elgersma, told councilthat creating the bypass around both the city's tanks is part of a list of requirements from the government of Nunavut to lift the order.

"It would also allow the city to have potable water that doesn't need to be boiled," said Elgersma, at the meeting.

She said the bypass would bring water from Lake Geraldine around the tanks and go through ultraviolet light treatment and chlorination before entering the above ground holding tank and entering the distribution system.

Normally, the city's water also runs through a sand filtration system to take out sediment and debris.

Elgersma said this could mean debris and sediment could enter the above ground reservoir and the distribution system. As a result there could be a need for additional flushing of the system.

This would mean the city would have to pump more water from the Apex River in the spring to make up for the loss at Lake Geraldine.

"Taste in the water may be different than residents are accustomed to given that the water isn't filtered," said Elgersma.

Shesaid the city is doing testing to see if there is an odour or a different taste in the water with the bypass.

Coun. Sheila Flaherty said residents have been complaining about the high levels of chlorine distributed from the refill tanks at the water depots, and asked if the water from the bypass will have similar chlorine levels.

"Raw water that is not filtered is more difficult to maintain consistent levels of chlorine," said Elgersma. "That is one disadvantage of doing any kind of bypass where you would bypass a filter."

The bypass will cost about $100,000 and could be completed as soon as Saturday.

Cause of contamination identified

During a presentation at a special city council meeting, representatives with WSP Canada, a water engineering firm hired by the city, said the entry point of the contamination was near the beginning of the water treatment process at the raw water storage tank, not at the contaminated north well like the city originally thought.

Ian Moran, a water treatment process design engineer with WSP,said the water passed through the system where the fuel had entered and accumulated in the first collection point at the north clear well.

"In isolating and bypassing that suspected point of entry, thereafter we saw a continual reduction in petroleum hydrocarbon concentrations leaving the water treatment plant," said Moran.

In the presentation Moran said on Oct. 24 the city discovered an area called the "void" where the source of the fuel was found from a rusted out fuel storage tank from 1962.

"The void is an area that is accessed via the basement of the water treatment plant," said Moran. "It is very difficult to access and requires specialized training for entry."

He said the void is a space between the water treatment plant and the exposed bedrock that works as an air barrier to insulate the plant.

Moran said water treatment plant operators have no reason to enter this space and thus didn't before Oct. 24.

"When the spill occurred we can only predict," said Charles Goss, a project manager with WSP, at the council meeting.

"But it could be anywhere from weeks, to months, to years, to decades ago."

However, Moran said even if the spill is old, it doesn't mean the water has been contaminated for a long time.

Moran said people are able to taste and smell hydrocarbons at very low concentrations, "far lower than we can even detect by instrumentation."

"Those very small amounts would have been the amounts people would have started to taste," said Moran. "We don't believe you've suffered a long period of time of contamination before it was detected."