CWQA Position Statement

Guidance for Issuing Boil-Water Advisories
 

Decisions concerning boil-water advisories can only be made at the local level based upon site-specific knowledge and conditions. The purpose of this guidance is to provide water purveyors and health and environment authorities with instructions on how to boil or disinfect tap water during a boil-water advisory and to summarize the important factors that should be considered before water advisories are issued or rescinded.

Instructions for Boiling and Disinfecting Tap Water

During a boil-water advisory, it is essential that all water destined for drinking, preparing formulas, juices and ice cubes, washing fruits and vegetables, cooking or dental; hygiene be boiled. Recent research indicates that holding water at a rolling boil for one minute will inactivate all waterborne pathogenic microorganisms. Water can be boiled in a pot or kettle on a stove, in an electric kettle without an automatic shut-off or in a microwave oven. If water is boiled in a microwave oven, it is advisable to include a glass rod or wooden or plastic stir stick in the container to provide nucleation sites for bubble formation and energy diffusion and prevent the formulation of superheated water. Under most circumstances, it is not necessary to boil water used for other household purposes. Adults, adolescents and older children may shower, bathe or wash using tap water, but should avoid swallowing the water. Toddlers and infants should be sponge bathed. Some local health authorities recommend that water for bathing and showering not contain more than 200 E.coli/100 ml as specified in the Guidelines for Canadian Recreational Water Quality.2 In non-outbreak situations, dishes and laundry may be washed in tap water, either by hand or by machine.

In the event of a waterborne outbreak, it may be necessary to advise the public to take precautions. In this situation, hands should be washed in a dilute solution of household bleach and water ( 1 mL or 20 drops of bleach per litre of water. This is particularly  important before preparing or eating meals and after using the toilet, changing diapers and handling animals. The solution should be allowed to stand for 10 minutes before use. If dishes are hand washed, they should be washed and rinsed in hot tap water, soaked in a dilute solution of household bleach (20 mL of bleach in 10 L of water) for one minute and air dried. Alternatively, dishwashers with a hot water cycle will disinfect dishes. These precautions should reduce the possible spread of illness and at the same time minimize the need to boil tap water and the risk of serious burns and scalds.

Click the links below for more information:

Water Talk- Boil Water Advisories and Boil Water Orders

Guidance for Issuing and Rescinding Boil Water Advisories