New tests have confirmed elevated lead levels in water at Yellowknife’s William McDonald School. Levels at Range Lake North School were within guidelines, the NWT government said.
Some of this month’s tests at William McDonald School recorded lead levels far, far higher than the Health Canada guideline value. In one case, a sample reported by the GNWT was more than 100 times the accepted level – and still 21 times that level even after a “flushing protocol” had been followed.
Recognizing the gravity of the situation, the GNWT said its health authority was mobilizing extra supports for affected families. “We understand that many families, educators, and community members will have questions,” the territory stated.
Fresh tests at both schools were ordered after earlier samples taken by the territorial government suggested a lead problem.
Those samples set off a chaotic chain of events when they were revealed in late May.
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The GNWT ended up questioning the validity of its own testing, saying those initial tests were carried out in a flawed manner and their results were poorly communicated.
While the first tests showing high lead levels had been recorded in January this year, senior leaders at the GNWT – including the education minister – confessed they had only been told more than four months later, once follow-up tests had appeared to confirm the issue.
An investigation into the circumstances of those initial tests, and the way the matter was handled, has been commissioned by education minister Caitlin Cleveland.
On Wednesday, results from an entirely new round of testing – ordered to try to sort out the mess left by the previous tests – were made public by the GNWT and YK1 school district.
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“Recent testing has confirmed elevated lead levels at École William McDonald Middle School and indicated that precautionary flushing will likely be needed at Range Lake North School,” the NWT government stated.
What did the tests find?
The new tests involved two approaches.
First, random samples were collected at both schools on May 27. Then, separate tests to “stress the system” – and figure out the maximum likely lead exposure – were carried out in mid-June.
At Range Lake North School, the random samples all came back within Health Canada guideline values. Three out of 24 stress-test samples came back above the guideline level before the pipes had been flushed, but dropped back into the zone considered safe once the water had been allowed to run for a while. (Health officials have maintained that no quantity of lead is truly safe, given its effects, but a minimal level is as good as can be hoped for.)
At William McDonald School, a much worse picture emerged.
The random sampling returned one sample, in a second-floor staff room, more than four times higher than the Health Canada guideline.
The stress-test sampling, though, was on a different level. In those tests, nine of 13 locations broke the guideline when tested after the water had been allowed to stagnate for some time.
At one location, the lead in the stagnated sample was measured at 566.5 micrograms per litre – well beyond the five-microgram Health Canada guideline. Another location was measured at 50.25, with a third at 45.3.
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While those values came down significantly once the water had been allowed to run for a time, all nine locations remained above the guideline. After the pipes had been flushed, a 10th location also crept above the five-microgram max.
What did the GNWT and YK1 say?
The GNWT did not directly comment on the scale of the lead detected in the water through the stress-test samples.
“Further work is needed to identify the source of elevated lead levels at École William MacDonald Middle School,” the territorial government stated.
“Investigations will continue to determine the cause and to identify appropriate mitigation and remediation measures. The water system will remain closed for drinking until these steps are completed.”
The territory noted that access to drinking water had been shut off at the school since May 27 and alternative water sources provided. The NWT’s chief public health officer has now formalized a “do not consume” order to that effect.
“The health and safety of students remains a top priority, and we will continue to update you as the situation evolves,” YK1 stated in a message of its own, published at the same time as the GNWT’s update.
What do I do if I’m worried?
The NWT’s health authority is “working to assign specific staff” to deal with concerned families and their needs in the days and weeks ahead, including offering appointments.
“Most children who have lead in their blood do not show immediate symptoms. However, even low levels of lead can result in subtle neurodevelopmental issues, particularly in young children,” the GNWT stated on Wednesday.
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“Preschool children can absorb approximately 40 percent of the lead they happen to ingest, while adults absorb only about 10 percent.
“If you are concerned about elevated lead levels, please contact Primary Care by completing the Callback Request Form and select ‘YK Primary Care Regarding Public Health Order’.”
The GNWT said once you get an appointment, you can have blood work done during the same visit. “Based on the level of need, a future pop-up clinic may also be scheduled,” the territory stated.
Note that no comparable testing of school drinking water for lead existing before late 2024. As a result, it’s not clear if there is any means by which the GNWT can establish when this problem began.
In recent years, William McDonald School hosted children from what is now named École Įtłʼǫ̀ while their facility was being rebuilt. The extent to which those families ought to consider themselves affected was not immediately clear.
What about water elsewhere in Yellowknife?
There is no suggestion that water anywhere else in Yellowknife is compromised by the issues identified at William McDonald School.
Yellowknife’s water, in general, goes through a series of tests at regular intervals. No lead concern has been identified.
More: Read the test results in full
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“Recent health monitoring in the NWT, conducted by the University of Ottawa and the University of Waterloo as part of the Health Effects Monitoring Program, tested residents of Yellowknife, Ndılǫ, and Dettah from 2017 to 2024,” the GNWT noted.
“This program found that blood lead levels in children and adults are generally low and well below public health intervention thresholds.”
However, that statement glossed over a finding that Cabin Radio reported from the same monitoring program in late 2024.
Publishing preliminary results from a long-term health study, researchers said they had identified an increase in lead levels among Yellowknife children and youth over the past five years.
The findings indicated that lead levels in biological samples taken from children aged three to 19 in Yellowknife increased between 2017-18 and 2023.
“It came as a surprise,” said Dr Laurie Chan, a professor at the University of Ottawa and Canada research chair in toxicology and environmental health, at the time the report came out.
The GNWT did not mention that finding in its Wednesday news release. No link has been definitively established between the researchers’ findings and the school drinking water lead tests. The researchers had left open the possibility that their preliminary findings may be a false alarm.
Earlier this month, the Health Effects Monitoring Program told us it is “currently focused on returning retest results to participants” and will later be able to share more “key population-level findings.”
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Are you affected?
If you and your family are affected by this announcement – either as a staff member, student or through some other means – we’d like to hear from you.
You can use this form to get in touch with us.
Emily Blake contributed reporting.
