High levels of lead detected in water at 2 Yellowknife schools

CBC

27-05-2025

Levels of lead that are higher than the maximum acceptable concentration have been detected in the drinking water at École William McDonald Middle School and Range Lake North School in Yellowknife.
Notices sent from the school board to parents and staff on Monday said lead levels in École William McDonald's drinking water were detected at 0.00903 milligrams per litre and 0.025 milligrams per litre at Range Lake school. Canada's drinking water guidelines state the maximum acceptable level is 0.005 milligrams per litre.
As a precaution, all sources of drinking and cooking water at the schools will be unavailable, the notices from Yellowknife Education District No. 1 (YK1) said.
Bottled water and bulk water dispensers will be provided for students and staff.
The notices said the water at the schools is safe for hand washing and cleaning.
In April, N.W.T.-wide testing took place for lead in school drinking water. A sample taken from the water fountain by the elevator on the first floor of William McDonald found the lead level at 0.00903 milligrams. A sample at Range Lake from the water fountain on the main floor near the staff room showed lead levels of 0.025 milligrams.
The single samples are not conclusive, the notices said. More testing needs to be completed to rule out sampling errors. The school board said the Department of Education, Culture and Employment is working with the Office of the Chief Public Health Officer to do so.
The notices said the city regularly tests for lead in drinking water and that treated water from the City of Yellowknife is safe to drink.
"Lead can enter drinking water when plumbing materials that contain lead corrode, especially where the water has high acidity or low mineral content that corrodes pipes and fixtures," it said.
The school board said it is working to identify potential sources of exposure.
"Exposure to high levels of lead over time can cause adverse health effects such as reduced cognition, increased blood pressure and renal dysfunction in adults, as well as adverse neurodevelopmental and behavioural effects in children," the notice said.
More water samples will be taken in the coming weeks, including all water fountains and cold water taps where water is used for drinking and food preparation.