Emergency Water Supply
During times of serious emergency, the normal water supply to your home may be cut off or become so polluted that it is undrinkable. You and your family may be on your own to secure a safe and adequate water supply, which may just be your most precious survival item.
Required Amounts of Drinking Water Per Person
Rule of thumb: One gallon of water is needed per person per day. A minimum of 14 gallons potable (drinkable) water per person would be needed for a two-week survival supply. With careful rationing, this amount would be sufficient for drinking, food preparation, brushing teeth, etc. An additional 1/2 to 1 gallon per person per day will allow for hygiene care. Individual needs vary, so the following must also be taken into account:
- Age, physical condition, activity, diet, and climate (hot Arizona summers may double the amount of water required per person)
- Children, pregnant and nursing mothers, and ill people require more water
Water Containers and Proper Storage
- Commercially available bottled water:
- Long-term storage (5+ years or observe expiration date)
- Sport bottles 1/2 to 11/2 liter sizes if kept in a cool, dark place 2 to 5 gallon polycarbonate waterbottles
- Short-term storage (6 months)
- One-gallon water containers similar to milk jugs will begin to disintegrate. They should be used and replaced every six months.
Preparing and Storing Bottles for Drinking Water
Keep the drinking water safe from contamination by carefully storing in clean, non-corrosive, tightly covered containers. Use cleaned and sanitized 2-liter soda bottles or one-gallon containers, preferably made of heavy opaque plastic with screw-on caps. Sport water bottles prepared commercially work well for long term storage. Plastic milk or fruit juice bottles are not recommended due to proteins and sugars that cannot be adequately removed providing an environment for bacterial growth.
- Wash bottles with soapy water, then rinse thoroughly.
- Sanitize bottles by adding a solution of 1 teaspoon of non-scented liquid chlorine bleach to a quart of water.
- Shake well; turning upside down a time or two so all surfaces of the container are touched.
- Let the mixture stand for 2 to 3 minutes, then pour it into the next container. You can use the same chlorinated water for several containers.
- Fill the empty sanitized bottle with tap water, and seal it tightly with cap or stopper.
- Label with "Drinking Water-Purified" and the date of preparation.
- Water purification tablets may also be used, and are available in drug stores and sporting goods stores. They are recommended for your First Aid Kit. Four tablets will purify one quart of water.
Some stored water may develop a disagreeable appearance, taste, or odor. These properties are not necessarily harmful. Inspect your water supply every few months to see whether the containers have leaked, or other undesirable conditions have developed. Replace every six months, or sooner if the water becomes contaminated.
Methods of Emergency Disinfection
Strain any sediment or particles from the water by pouring through several layers of cheesecloth, paper towels, or coffee filters. Then use one of the following purification methods:
- Boiling - Vigorous boiling (rolling boil) for ONE FULL minute will kill any disease-causing bacteria present in water. The flat taste of boiled water can be improved by pouring it back and forth from one container into another, by allowing it to stand for a few hours, or by adding a small pinch of salt for each quart of water boiled
- Chemical Treatment - When boiling is not practical, chemical disinfection should be used. The best commonly available chemical is chlorine.
- Chlorine Bleach - Common unscented household bleach will disinfect water, and the procedure is usually written on the label. If it is not, find the percentage of available chlorine (usually 5.25%) on the label and use the following information as a guide:
|Water Amount||Cloudy Water||Clear Water|
|1 quart||4 drops||2 drops|
|1 gallon||16 drops||8 drops|
|5 gallons||1 teaspoon||1/2 teaspoon|
|55 gallons||4 tablespoons||2 tablespoons|
The treated water should be mixed thoroughly and allowed to stand for 30 minutes. The water should have a slight chlorine odor, if not, repeat the dosage and allow the water to stand for an additional 15 minutes. If the treated water has too strong a chlorine taste, it can be made more palatable by allowing the water to stand exposed to the air for a few hours or by pouring it from one clean container to another several times.
- Solar water disinfection research
For more information about Purification and Water Storage
Please contact the Water Quality division at 480-644-6461.