Boil Water Advisories

A boil water advisory is issued when the community’s drinking water supply has, or may have, germs that can make people sick. Boiling water kills these germs. The advisory provides information to residents on how to use their water safely and what precautions to take.

Process of issuing and lifting a boil water advisory

Public Health’s Medical Officer of Health in collaboration with the local municipality and drinking water operator issues a boil water advisory for various reasons, for example:

  • The laboratory has confirmed that bacteria, viruses or parasites are in the drinking water.
  • A water main has broken or there has been severe flooding.
  • There is not enough disinfectant in the water to treat possible sources of contamination.
  • There is suspicion of illness related to the water.

It is the responsibility of the drinking water operator to notify affected users that a boil water advisory has been issued by Public Health and the water is unsafe for consumption.

The Medical Officer of Health is responsible for determining the how long a boil water advisory will last, based on many factors, like sampling results and if there are ongoing concerns about the water quality. The advisory will remain in effect until written notification is issued and samples collected indicate the water is safe for drinking.

How to use your water safely

To boil, bring your tap water to a rapid, rolling boil for 1 minute. Let the water cool before drinking. Boiled water can be stored in the refrigerator in clean containers until needed.

Use bottled water or boiled water for:

  • Drinking (for people and pets)
  • Washing fruits and vegetables
  • Making juice, tea and coffee
  • Preparing food and baby formula
  • Making ice
  • Brushing teeth and soaking dentures

Remember:

  • Boil tap water even if it is filtered (for example, by an under sink or tap water filter or a pitcher/jug that filters water).
  • Do not use water from any appliance connected to your water line, such as ice and water from a refrigerator.
  • Discard all ice, formula and juices that were made before the boil water advisory was issued.
Hand Washing

Safely wash your hands by:

  • Washing with bottled water or cooled, boiled water.
  • Washing with tap water and soap, then dry thoroughly and sanitize your hands using:
    • An alcohol-based hand sanitizer containing more than 60% alcohol, or
    • Rinse in a mild bleach solution by mixing 1 tsp of liquid household bleach for every 4.5 L of water. Let solution stand for 15 minutes before using.

Important: Keep bleach and bleach solution out of the reach of children. Do not drink bleach solution.

Showering/bathing

Tap water can be safely used for adults/older children who can be careful not to swallow any water.

Babies and young children are more likely to ingest water and should be given a sponge bath instead.

Dishwashing, laundry and cleaning

  • Dishes can be washed by hand with tap water and soap, followed by rinsing or sanitizing:
    • Rinse the dishes in boiled water or
    • Sanitize with a strong bleach solution by mixing 1 tsp of liquid household bleach for every 3 cups of water. Let stand for 15 minutes before using. Let dishes sit in the disinfectant for at least one minute then air dry.
  • Dishes can be washed in the dishwasher if:
    • The temperature during the final rinse reaches at least at least 150 degrees Fahrenheit (66°Celsius)
    • A sanitize cycle is used.
  • Laundry can be done as usual.
  • Cleaning of surfaces can be done using soap and water then sanitizing with a strong bleach solution by mixing 1 tsp of liquid household bleach in 3 cups of water. Let stand for 15 minutes before using. Spray or wipe on the surface.

Important: Keep bleach and bleach solution out of the reach of children. Do not drink bleach solution.

Watering plants and gardens

Water plants and gardens with tap water as usual.

After the advisory is lifted

To ensure the water in your home is safe:

  • Run cold water faucets/fountains for approximately 1 minute before using the water.
  • Flush garden hoses by running cold water through them for at least 1 minute. 
  • Replace all water filters such as those under the sink, in appliances such as refrigerators and in water jugs.

Other types of Drinking Water Advisories

Sometimes, boiling water is not enough to eliminate the problem, especially if the issue is related to chemical contamination.

  • In the event of a Do Not Drink Water Advisory, even if boiled, the water is not safe to drink and an alternate source of water must be used.
  • In the event of a Do Not Use Water Advisory, water from the drinking water system must not be used under any circumstances and avoid skin contact.

It is very important to pay attention to and follow any Drinking Water Advisories issued in your community to keep you and your family safe and healthy. 

More information