What is a Boil Water Advisory (BWA)?

A BWA is a public notice issued by the Medical Officer of Health to protect public health. Residents are advised to boil their water before consuming it to prevent illness from disease-causing microorganisms that may be present in the municipal water supply.

A BWA remains in place until laboratory testing confirms the safety of the water supply, and the Medical Officer of Health lifts the advisory.

Why is a BWA issued?

A BWA may be issued for a number of reasons, such as:

• test results indicate the presence of bacteria in the water supply; or
• there is a risk of bacterial contamination due to a watermain break or a mechanical problem.

How would I be notified if there is a BWA?

Halton Region may communicate a BWA in the following ways:

• Letter to homes/businesses
• Media release to alert local news outlets
• Automated phone call
• halton.ca
• Social media (Twitter, Facebook, Instagram)
• 311 call centre

How do I use water safely during a BWA?

Bring the tap water to a rolling boil for at least ONE MINUTE before using it to:

• drink
• prepare food, including ice and hot/cold drinks
• make infant formula or food for baby
• wash fruits, vegetables and other food
• brush teeth, gargle and rinse dentures

Boiled water can be cooled, stored in a clean and sanitized food container with a lid, and refrigerated.

Are there alternatives to boiling tap water?

Yes. Commercially bottled water or water from a public drinking water supply that is not affected by the advisory can be used.

Can the tap water be used for showering and bathing during a BWA?

• Adults, teens and older children may shower or bathe using tap water, but should avoid swallowing the water. Babies and young children can be given sponge baths instead of tub baths or showers.
• Use boiled (and cooled) or bottled water for handwashing. Alcohol-based (60-90 per cent alcohol) hand rub can be used when hands are not visibly dirty.

How do I wash dishes during a BWA?

• Dishwashers that use hot water (final rinse temperature of at least 65ºC) or have a sanitizing cycle will disinfect dishes.
• Use boiled or bottled water to wash and rinse dishes by hand. Or, use tap water to wash and rinse dishes, then soak them in a bleach and water solution for at least one minute and let them air dry. A bleach and water solution can be made by mixing 30 mL of liquid household bleach in 13.5 litres of lukewarm water.

Should I change the way I do laundry?

No, laundry can be done as usual.

What should I do if I am immunocompromised (e.g., have a weakened immune system) and I am concerned?

It is best to follow your physician’s advice.

Do I need to boil my water if I have a water filter?

Yes. Household water filters, such as activated carbon filters, typically do not remove bacteria or viruses.

Can tap water be used to fill wading pools for children?

No. The water is not safe to use in wading pools or for water play because children may swallow it.

What do I do when the BWA is over?

Before drinking the water:

• run cold water faucets for one minute or until the water feels cold.
• run water softeners through a regeneration cycle.
• drain and refill hot water heaters set below 45°C (113°F). Normal setting is 60°C.
• replace water filters and follow manufacturer’s instructions for cleaning and sanitizing appliances with water line connections.

Who can I contact for more information?

Please email accesshalton@halton.ca or call 311.