Water advisory issued for Fort Liard, N.W.T., because of chemical byproducts

Residents in Fort Liard, N.W.T., are being advised to use filtered or bottled water and take other measures to protect themselves from high levels of disinfection byproducts called trihalomethanes in the tap water.

In an advisory issue on Monday, territorial health officials said recent lab tests from the Hamlet of Fort Liard show total trihalomethane (THM) levels in tap water are above Health Canada guidelines.

Health officials say the advisory is "precautionary," and the health risk is considered "minimal, as only long-term (over 70 years) exposure to THMs is expected to cause serious illness."

THMs are chemical compounds, such as chloroform, that can form when chlorine is used to disinfect water and reacts with organic matter.

In Fort Liard, chloroform was the main THM found in the water. Officials say the level of THMs detected in the hamlet "have never reached the level where chloroform could cause health effects."

Still, residents in Fort Liard are advised to either:

Residents are also advised to use filtered or bottled water for cooking, though tap water can be used for washing produce. Tap water can also be used for brushing teeth, washing and for laundry.

THMs can also evaporate, so residents are advised to ventilate the room when boiling or steaming vegetables, or when taking a shower or bath. Showers should be less than 10 minutes and baths less than 30 minutes, to minimize exposure to vapours, the advisory states.

It also refers to climate change and aging infrastructure as factors causing more organic materials to be in treated water. It says the hamlet has been working with the territory since October on short-term measures to reduce THMs, and that "work continues on a long-term solution."

A similar advisory related to THMs was issued last month for people living in Hay River, Enterprise, Kátł'odeeche First Nation and Kakisa, N.W.T.