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Water treatment plant goes online
Facility began official operation Friday ending month-long boil water advisory

Shane Magee
Northern News Services
Wednesday, June 17, 2015

A month-long boil water advisory ended Friday when the city's water treatment plant was deemed ready to operate continuously.

High turbidity - or dirt - in the Yellowknife River, which supplies the city's drinking water, prompted the advisory that began May 11.

Chris Greencorn, the city's director of public works and engineering, said the plant had been running for about two weeks but was going through testing before the advisory could be lifted.

"The reason we didn't lift the boil water order immediately is because we may have had to shut it down to tweak something or may have had to make changes in the process," Greencorn said Friday. "One day we had kinks with the chlorine generator and had to shut it down. So we didn't want to lift (the advisory), put it back in place, lift it, and put it back in place."

Greencorn said the approximately 22,000-square-foot plant is expected to prevent future boil water advisories because of the filtration system. The advisory began when the Nephelometric Turbidity Unit (NTU), a measure of the turbidity level, reached 10 NTU in early May. At one point, the NTU level spiked to 20. The water is still coming muddy but the plant's filtration system brings the level down to 0.15 NTU.

Asked how construction went, Greencorn said "flawlessly, for the most part."

Some work, such as lighting and painting, still needs to be done at the site of the treatment plant on Tin Can Hill by contractors before the city accepts the facility as complete, Greencorn said.

Estimated to cost $32.5 million, the final cost is expected to be revealed in July or August once bills come in, Greencorn said, adding it won't be "millions" over budget.

The plant will cost about $500,000 annually to run with a staff of three who work eight-hour shifts, Greencorn said. That's down from the five staff who used to be required at the pumphouse, which had to be staffed at all times. Greencorn said two long-time city employees retired, meaning no one had to be let go.

The plant can treat up to 20 million litres per day although the city is only using about 10 million litres per day based on the current population.

Water is collected from the Yellowknife River where a grate blocks larger debris and fish. Water goes through Pumphouse No. 2 eight kilometres through a pipeline under Great Slave Lake before reaching the plant.

It is then forced through a filtration system that cleans the water of small debris. Chlorine to deal with any bacteria and fluoride to prevent tooth decay are added before the water goes out to a reservoir and then through the distribution system.

The facility, Greencorn said, will make the city a leader for water treatment in the North. He envisions it as a training centre for people working in other plants. It includes a classroom space for that purpose.

Several decisions prior to completion of the facility were controversial.

City officials, including the mayor, said GNWT legislation adopted in 2009 meant a new facility with a filtration system needed to be built, despite the river providing excellent quality water.

Following that, the city contracted construction to Ontario-based NAC Contractors Ltd. over two Northern firms - Det'on Cho Nahanni Construction, and Clark Builders - because the southern company submitted a slightly cheaper bid.

The city set aside $21 million for the work, but decided to spend $17 million of it on other projects, such as roads and water and sewer infrastructure. It borrowed $23.8-million, to be repaid over 15 years.

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