Residential water use after a wildfire event

On this page

• Wildfire impacts on water sources
• Using municipally supplied tap water after a wildfire event
• Using private water systems after a wildfire event

Wildfire impacts on water sources

Some communities across Canada regularly experience wildfire events. This is expected to continue as Canada's changing climate provides ideal conditions for more frequent wildfires and longer wildfire seasons. Wildfire season typically runs from early April to late October.

Many factors influence whether, and how much, a wildfire impacts water sources, including:

• how severe the burn was
• how much area was burned
• how close the fire came to the water source
• the way the water flows in the region (regional hydrology)

Some of the ways that wildfires can impact water sources are:

• new or worsening algal blooms in water sources
• changes in water quality, including:
  • increased pH
  • increased in total organic carbon
  • increased concentrations of metals, such as manganese, iron and aluminum
  • increased concentration of nutrients, such as nitrites, nitrates and phosphorus
  • increased numbers of particles, such as silt or sand, floating or suspended in the water (total suspended solids)
• chemical contamination of drinking water, for example by fire retardants
• changes in taste, colour and smell of drinking water

These impacts can make it harder for water treatment operators to treat water sources effectively. However, water treatment facilities are designed to remove contaminants and provide safe drinking water, even in challenging conditions.

After a wildfire event has occurred in your community, it's extremely important that you don't use tap water for drinking or preparing food until officials say the water source is safe. Don't use tap water for:

• drinking
• making ice
• washing food
• giving to pets
• brushing your teeth
• washing your hands
• making baby formula
• preparing food and drinks

Using municipally supplied tap water after a wildfire event

Your water supplier is responsible for testing the quality of drinking water distributed through municipal systems.

If your community has been affected by a wildfire event, it's possible that local authorities turned off the supply of electricity and drinking water to your home.

• Don't turn utilities back on until they have been checked by your local utility provider.
• Follow the instructions for all drinking water advisories and notices sent to your community or residence.

Once you have been informed by your water supplier that it's safe to use your tap water:

• flush your water system before you use it:
  • open all taps in the home and run all cold and hot water taps for at least 5 minutes
  • follow any additional flushing directions provided by your water supplier

Using private water systems after a wildfire event

If your water comes from your own private well or surface water (for example, from a lake), it's your responsibility to make sure that the quality of your well water is protected.

Before using your well, contact your local public health authority for advice on water quality and testing and additional measures, such as flushing. Have an accredited laboratory test the water.

Visit Well water and health to learn which chemicals to test for if:

• your septic system was damaged by fire
• your fuel storage tank was damaged by fire
• your well, water components or equipment were damaged by fire

Related links

• What to do in a wildfire emergency
• Preparing for wildfire smoke events
• Wildfire smoke, air quality and your health

For more information visit www.canada.ca/waterhealth or contact us at water-eau@hc-sc.gc.ca.