City to debate water source switch
Decision on replacing $20M pipeline supplying drinking water from Yellowknife River nears
Shane Magee
Northern News Services
Friday, May 20, 2016
SOMBA K'E/YELLOWKNIFE
In mid-June, city councillors are expected to weigh switching the drinking water supply from the Yellowknife River to Yellowknife Bay, a potentially hot button debate touching on fears of arsenic contamination.
The city currently draws water from the river through an eight kilometre pipeline leading to its new treatment plant. The 16-inch diameter pipe, installed in the 1960s, is scheduled to be replaced in 2020 at a cost of $20 million - double the estimate from five years ago, though a detailed estimate has not yet been done.
The decision on the pipeline would be made by this council as the city prepares its three-year capital budget plan, officials have previously said.
The city has a backup intake line that can pull water from Yellowknife Bay, closer to the new water treatment plant. The line is used infrequently, but previously when a pumping station was undergoing maintenance and during the commissioning of the water treatment plant.
That usage triggered concerns from the Yellowknives Dene First Nation and North Slave Metis Alliance about potential health impacts of arsenic from the water and sediment on the lake bed, according to regulatory documents filed online.
"YKDFN would like further assurance that the city has no intention to draw drinking water from YK Bay. Further, we would like to see some type of institutional mechanism making it more difficult for future city leadership to draw drinking water from Yellowknife Bay," the document from April posted to the Mackenzie Valley Land and Water Board (MVLWB) registry states.
The response came as the city sought to use bay water temporarily during the commissioning of the water treatment plant.
Chris Greencorn, the city's director of public works and engineering, has said the water is safe and is regularly tested.
An ongoing study of the environmental impact of Giant Mine led by Environment Canada, with multiple partners including the territorial government and First Nations, released data on water quality testing at six locations, one close by the water intake line in Yellowknife Bay. The intake sits about 1.5 metres above the lake bed which is meant to prevent sediment from entering it. Testing done in September 2014 was pointed to in the comments posted on the registry about drawing drinking water from the bay, having found total arsenic concentrations at about 1.9 parts per billion at the bottom of the lake. This is well below the Health Canada drinking water guideline of 10 parts per billion.
Of the six areas tested, the highest concentration was 2.8 parts per billion on the bottom of a site in Back Bay.
If the water is safe, Coun. Niels Konge questioned why the city would spend the money to replace the lengthy pipeline to Yellowknife River.
"That's what we need to know - if the water is fine coming out of the bay, it doesn't make sense going and spending $20 million to replace the pipeline," said Konge, who has asked for the debate to take place. "But if the water in the bay is not safe, then it's not a waste."
He said he hasn't taken a position and wants more information.
"I'm just hoping that we can get some clear scientific information," Konge said.
The debate isn't a new one. Before the water treatment plant was built the topic was raised but shot down because of concerns about potential arsenic contamination.
After Baker Creek overflowed into tailings ponds at the Giant Mine site in 2011, Dettah Chief Ed Sangris warned against changes to the water supply.
"You know how the city talks about switching the water intake from the river to the bay, well if the mayor's not careful, he's going to kill everybody in Yellowknife because stuff like this goes on," Sangris said.
Dr. Andre Corriveau, the territory's chief public health officer, wasn't available to comment on the issue this week.
The Department of Health and Social Services pointed to a response it provided the Mackenzie Valley Land and Water Board in April regarding the city's request to temporarily use bay water.
Jeremy Roberts, an environmental health officer, stated the public health office reviewed monthly arsenic test results from a wet well in the bay. Arsenic levels have always been below the required 10 parts per billion, the document states. The department stated that monthly testing for arsenic "will greatly help in the handling of any future drinking water safety considerations that pertain to the Public Health Act."
In the same document, William Lines of Yellowknives Dene First Nation stated the city should notify the public any time it intends to use bay water as well as post information on its website about potential health implications of arsenic contamination. The city in response stated it doesn't intend to issue advisories since arsenic levels fall below Health Canada guidelines.
The MVLWB, which has no jurisdiction over drinking water quality, noted if the city intends to draw from the bay for non-emergency use it can apply to amend its water license.
The city debate is expected June 13 as part of the regular municipal services committee meeting in council chambers.
