Boil water for ONE HOUR warnings.
If the emergency has left you with no way to boil the water or if you have limited fuel and do not want to use it for boiling water, you may treat the water with liquid chlorine laundry bleach. NOTE: do not use scented laundry bleach, powdered bleach, or swimming pool chlorine; these contain additional chemicals that are poisonous. Below is a chart that indicates how much liquid bleach to add to the water.
Amount of water
Amount of bleach to add to clear water
Amount of bleach to add to cloudy/dirty water
1 gallon
8 drops
16 drops
5 gallons
1/2 teaspoon
1 teaspoon
After you add the bleach, thoroughly mix by stirring or shaking the container. Let the water stand for 30 minutes before using. A slight chlorine odor should be noticeable in the water; if not, add another dosage of bleach and allow the water to stand another 15 minutes before using. The water can also be treated with the use of water purification tablets that can be purchased at most outdoors or sporting goods stores. Follow the directions for use on the package you purchase. Treat only enough water to meet your needs for 48 hours at a time. There is an increased chance of recontamination if the treated water sits for more than 48 hours. Refrigeration will also help prevent recontamination.
Note: Most home water filters are meant for water that is already microbiologically safe. Using these filters during a "boil water notice" will not guarantee the safety of the water. Replace any filter cartridges after the boil water notice has been lifted to ensure your filter is not contaminated.
Okay - I've boiled a fair amount of drinking water in my time, and I'm not aware of anything that takes boiling for an hour to kill. Anyone know the purpose of this?