Water Safety : Safe Drinking Water During A Power Failure

During a power failure, the water supplied to your home by your local water utility may no longer be safe to drink without treatment. Pumps used to pressurize water mains may fail and parts of the water treatment plant necessary for water purification may not operate properly. This threatens the safety of the water.

That is why, during power failures, the safety of your water supply must be confirmed before using it for drinking, brushing teeth, washing fruits and vegetables, preparing drinks, baby formula or foods that won't be cooked.

It is also important to note that during a power outage, your local water utility may have a limited or reduced supply of water. As a result, you may also be asked to conserve water to prevent severe shortages.

If a Boil Water Advisory has been issued by your local health unit, there is likely a problem with the safety of the water. In this case, do not drink the water. Use an alternate source of safe water, such as commercially bottled water or follow the instructions below for treating tap water when a Boil Water Advisory has been issued.

A boil water advisory will be communicated by municipal water works officials and the local medical officer of health through the local media. You can also contact your local public health unit for this information.

When a Boil Water Advisory has been issued, or if you cannot confirm whether a Boil Water Advisory has been issued and are concerned about the safety of the water, use an alternate source of water or treat the water using one of the following methods :

1. Bring the water to a rolling boil for at least one minute (water should be bubbling and rolling).
   
   
   If you are using a gas barbecue to boil water, use it only outdoors.
   
   During a power outage, never use gasoline or charcoal-burning devices, such as generators, grills, or camp stoves, inside your home, basement, or garage; or near a window. Carbon monoxide from these sources can build up in your home and poison the people and animals inside.



2. If water cannot be boiled, add six drops of newly purchased liquid household bleach (unscented, 4 to 6 per cent chlorine) per gallon (4.55 Litres) of water. Stir well and let the water stand for 30 minutes before using it. If you are going to make infant formula with the water, let the water stand overnight, covered with a clean paper towel or a loose lid, in a cooler or refrigerator before use. This will allow the bleach to do its job and then dissipate so that the bleach does not affect the taste of the formula.



3. You may also use water purification tablets from your local pharmacy to treat tap water. Follow the directions on the label. Let the water stand overnight, uncovered, in a cooler or refrigerator. This will allow the purification tablet to do its job and then dissipate before use.

If you use the water from your own well, a power outage will normally cause the water pump to fail. Use an alternate source of safe water, such as commercially bottled water or follow the instructions above for treating tap water.

If you have a back-up power generator, use the water as you did before the power failure. Make sure that any water purification system you may use, such as an ultraviolet light, also continues to operate.

See also :

• How to prepare baby formula
• Keeping food safe during a power failure
• Food Safety
• Water Safety

• The Canadian Partnership for Consumer Food Safety Education
• The Ontario Ministry of Agriculture and Food
• The Canadian Food Inspection Agency

Or, contact your local public health unit.

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