More water testing confirms high levels of lead at Yellowknife's William McDonald school

Luke Carroll · CBC News

· Posted: Jun 25, 2025 5:23 PM EDT | Last Updated: 7 minutes ago

High levels of pb person been confirmed successful the h2o astatine William McDonald School successful Yellowknife aft different circular of testing.

The N.W.T.'s main nationalist wellness serviceman has formally issued do-not-consume orders for the h2o astatine William McDonald, arsenic good arsenic Range Lake North. The orders travel a period aft parents and unit astatine the schools were informed precocious pb levels had been detected astatine some schools.

On Wednesday, the schoolhouse committee sent different update to parents saying further investigating was completed connected May 27 arsenic good arsenic June 12 and 13. It said a "flushing protocol" to fto the h2o tally concisely earlier usage would beryllium required astatine Range Lake North.

It said much enactment would person to beryllium done to place wherever precocious pb levels are coming from astatine William McDonald, and place however to mitigate it.

"The h2o strategy volition stay closed for drinking until these steps are completed," it wrote.

Shortly thereafter, the N.W.T. authorities released the results of its follow-up investigating successful a quality release.

The authorities said it had 2 types of tests done, some of which showed elevated pb levels astatine parts of William McDonald. Only one type of investigating — which it described arsenic a "stress test" designed to beryllium much apt to amusement higher pb levels — showed precocious results astatine parts of Range Lake North.

Meanwhile astatine William McDonald, portion the different benignant of investigating — random sampling — Meanwhile astatine William McDonald, portion the different benignant of investigating — random sampling — showed elevated pb levels astatine 7 of 13 spots, the accent trial showed importantly more, with 1 determination showing 566.5 micrograms of pb per litre earlier the h2o was flushed, and 105.7 micrograms after.

Health Canada's guidelines telephone for levels nary higher than 5 micrograms per litre.

The territorial authorities said the results are portion of an ongoing appraisal of pb successful schoolhouse drinking h2o systems being conducted by engineering and biology consulting steadfast Stantec. It said the last study summarizing the findings is expected "shortly."

The merchandise says that "most children who person pb successful their humor bash not amusement contiguous symptoms." 

"However, adjacent debased levels of pb tin effect successful subtle neurodevelopmental issues, peculiarly successful young children."

The update besides cited caller wellness monitoring by the University of Ottawa and University of Waterloo that tested residents successful Yellowknife, Ndılǫ, and Dettah from 2017 to 2024. 

It recovered pb levels successful children and parents to beryllium low. 

The merchandise said the territorial authorities volition proceed to stock updates connected the situation. 

"We recognize that galore families, educators, and assemblage members volition person questions," the merchandise says.

"While the last Stantec study is inactive pending, this update reflects trial results that enactment the continuation of existing mitigation measures. We volition proceed to support residents informed and volition stock verified updates — including the last study — arsenic soon arsenic they are available."