This page provides answers to common questions about the drinking water advisory issued on November 3, 2025. It applies to residents of Hay River, Enterprise, Kátł’odeeche First Nation, and Ka'a'gee Tu First Nation (Kakisa).

Why this advisory was issued

The Chief Environmental Health Officer has issued a drinking water advisory for four communities due to elevated levels of Trihalomethanes (THMs) in the water supply.

THMs are by-products that form when chlorine used to disinfect drinking water reacts with natural materials like decaying plants and other organic materials. Long-term exposure to high levels of THMs (over 70 years) may increase the risk of cancer. No illnesses have been reported.

Affected communities:

• Town of Hay River
• Hamlet of Enterprise
• Kátł’odeeche First Nation
• Ka'a'gee Tu First Nation (Kakisa)

If you live outside these communities, your water is not affected.

Why chlorine is needed to disinfect water

Chlorine is used to disinfect drinking water and kill bacteria and viruses that can cause serious illness. Without chlorine, the health risks from micro-organisms would be much greater than the risks from THMs.

How to reduce your exposure to THMs in drinking water

You can reduce your exposure to THMs by:

• Filling a pitcher with tap water and leaving it uncovered in the fridge for 24 hours
• Using a pour-over water filter (e.g., Brita) or a filter certified to remove THMs (NSF/ANSI 53)
• Following manufacturer instructions for installing and replacing filters
• Using bottled water
• Boiling water for baby formula for 1 minute, uncovered, before use

How to use tap water safely for cooking, cleaning and bathing

Cooking and cleaning

• Use filtered or bottled water for cooking
• Ventilate your kitchen when boiling or steaming tap water
• Tap water is safe for washing fruits, vegetables, dishes, and hands
• Tap water is safe for household cleaning

Bathing and household use

• Keep showers under 10 minutes and baths under 30 minutes
• Open windows or use a fan to ventilate the bathroom
• Tap water is safe for brushing teeth and doing laundry

Health conditions

If you have a chronic lung condition or use oxygen support, THMs may make your symptoms worse . Please follow our guidance for reducing THM exposure and contact your healthcare providers if you are experiencing any worsening respiratory symptoms.

Why THMs are higher than usual

Trihalomethanes are by-products that form when chlorine reacts with natural materials in water. Due to changing nature of the lake water, higher amount of organic materials are coming is entering the source water for the Hay River treatment plant. The current plant design not able to remove all those organic materials, which is creating more disinfection by-products than expected.

Is the water safe to drink?

Yes, the water remains safe for many daily uses. The public health advisory is a precautionary measure to inform residents about protective actions they can take for themselves and their families.

These include using water filters, letting water sit uncovered in the fridge for 24 hours, or using bottled water.

Long-term exposure to high levels of THMs (over 70 years) may increase the risk of cancer. THM levels in the drinking water have been regularly monitored. They were within acceptable limits as recently as the summer of 2024, and this year’s elevated levels represent a short-term exposure, which poses a very low health risk.

If you have a lung or respiratory condition

People with pre-existing lung and respiratory condition may be more sensitive to THMs in steam. To reduce exposure:

• Use well-ventilated spaces when showering or bathing.
• Consider water filtration systems that reduce THM levels, such as activated carbon filters.
• Limit exposure to steam from chlorinated water, especially if you notice worsening symptoms after bathing.
• Consult your healthcare provider if you suspect environmental factors like THMs are affecting your condition.

What’s being done to lower THM levels

The Town of Hay River is scheduled to optimize its water treatment plant in November 2025. This means making technical changes to reduce the amount of organic material in the water that reacts with chlorine to form THMs.

A number of actions are being considered to reduce the THMs in the water, and more frequent sampling is being done.

Monthly water testing will continue to monitor THM levels and ensure water quality remains safe.

The advisory will remain in place until THM levels are reduced and consistent testing confirms the water meets safety standards. Residents will be informed when the advisory is lifted.

If you have questions or need help

For questions or concerns, contact an Environmental Health Officer.