Escherichia coli (E. coli), fecal coliforms or enterococci

The presence of these microorganisms in water indicates that it has been contaminated with stool. Such contaminated water can contain microbes (bacteria, viruses or parasites) that cause health problems. To be safe, drinking water should not contain any of these micro organisms.

Health risks

Water contaminated with micro-organisms can cause gastroenteritis, the symptoms of which include:

  • Diarrhea
  • Abdominal cramps
  • Nausea
  • Vomiting 

Protection and prevention

As soon the head of the drinking water distribution system is notified of the presence of Escherichia coli or fecal coliforms in the water supply, they must issue a boil water advisory.

A precautionary boil water advisory may also be issued in situations potentially affecting the microbiological quality of the water, such as the inadequate disinfection of drinking water or a water main break or repair.

Steps to take during a boil water advisory

Bring water to a rolling boil for at least one minute before consumption, or use bottled water to:

  • Drink
  • Prepare beverages
  • Prepare baby bottles and baby food
  • Wash fruits and vegetables to be eaten raw
  • Make ice
  • Brush your teeth and rinse your mouth

You may use tap water without boiling it to:

  • Wash dishes with hot water
  • Wash clothes
  • Wash hands with hot, soapy water
  • Take a shower or a bath

Make sure that babies and young children do not swallow water when taking a bath. You can also bathe them with a washcloth.