Knowing How Much Water Is Enough
Store at least one gallon of water per person per day. Keep in mind that although this is a good estimate, everyone's needs differ depending on age, physical condition, activity, size, diet, and weather. A normally active person needs to drink at least two quarts of water per day. In hot environments twice that amount may be needed. Therefore, store more water for children, pregnant women, nursing mothers, and ill people. Additional water is needed for food preparation and hygiene. You can reduce the amount of water your body needs by decreasing activity and staying cool.
Choosing a Water Container
Thoroughly washed, rinsed, and sanitized plastic, glass, fiberglass, or enamel-lined metal food-grade containers are appropriate for storing water. Plastic containers such as soft drink bottles or purchased food-grade plastic drums (intended for water or food) are best.
Never use a container that has held toxic (poisonous) substances. Tiny amounts of the toxic substance can remain in the pores of a plastic container, regardless of how well you clean it. Do not use plastic milk jugs because they are impossible to clean properly, the lids do not seal well, and they are usually made from biodegradable plastics that will break down over time, causing leaks and possibly allowing contaminated air to enter. Finally, do not store water in unlined steel, stainless steel, aluminum, or iron containers because undesirable substances from the containers may leach into the water.
Sanitizing a Water Container
Before bottling any water, you will need to wash, rinse, and sanitize the container. This process should take only a few minutes. Add 1 tablespoon of common household bleach, which contains 5.25 percent sodium hypochlorite, to one gallon of water. Pour a little of the solution into the container that will store water. Cap the container and shake it up and down thoroughly. Let it stand for about a minute. Empty out the sanitizing solution. The container is now ready to store water.
Storing Tap and Purchased Water
Under ordinary conditions, if you receive water from a public supply and not from a private well, you do not need to treat your water before bottling it. All storage containers need to be thoroughly washed, rinsed, and sanitized before they are filled with water. (See previous section for how to sanitize a container.)
Before storing tap water from a private well, disinfect it to prevent the growth of microorganisms. Use liquid household chlorine bleach that contains 5.25 percent sodium hypochlorite and no soap. Do not use scented or "color safe" bleaches or bleaches with added cleaners. Some bleach containers warn, "Not For Personal Use." You can disregard these warnings if the label states sodium hypochlorite is the only active ingredient and if you use only the small quantities in these instructions. Add four drops of bleach per quart of water and stir. Seal your water containers tightly and label them ('Disinfected Drinking Water').
Replace the water every three to six months with new, disinfected water. Always keep commercially purchased water in its original sealed container. Generally, the shelf life is one year. Do not store larger containers, such as five-gallon jugs, for more than six months.
Light can cause plastic containers to degrade, so store water in cool, dark places, away from sunlight and fluorescent lighting. Closets are good storage spaces. Store water away from items that have a scent or perfume (such as laundry soap or air fresheners) and away from gasoline, kerosene, pesticides, and other chemicals. Vapors from these chemicals can permeate the plastic and contaminate the water. To extend the shelf life of water stored in transparent containers, place the containers together in dark plastic bags to keep out the light.
You can also store water in the freezer. Being frozen keeps water at an acceptable quality for a longer time, and the presence of this ice in the freezer will help keep food from thawing in the event of a power outage. Keep in mind that when you store water by freezing it, you should not fill the container all the way because water expands as it freezes. For this reason, it is best to use a plastic container instead of a glass one.
Finding Other Sources of Drinking Water
If you haven't stored water for emergency use, you do have some other options. Most homes contain sources of water you might not think to use. Remember, however, that during an emergency, water from wells, cisterns, and other delivery systems may be unsafe and should be disinfected. Other home sources of water are the following:
To obtain water from your water heater, turn off the power supply to the heater. For example, turn off the gas at the intake valve or turn off the electric circuit breaker or unplug the unit. If you have lost water because of a water main break, take extreme care when removing water from the heater or your house's plumbing. Open a faucet or two on an upper level of the house and drain the water from the water heater or from a faucet on a lower level. Draining water without opening the extra faucets can create a suction in the broken main and possibly draw contaminated water into the plumbing system. Opening the faucets, even if a line is not broken, will make it easier to get water from your plumbing or water heater.
As a last resort, you can use water in the reservoir tank of your toilet (not the bowl), but disinfect it first by boiling it. Do not use this water if it contains a disinfectant or bowl cleaning tablets or solutions.
If an emergency arises quickly, you can fill containers and bathtubs with water. This water can be disinfected immediately before use.
Adapted from: Water Treatment Notes, Water for Emergency Use, Katrie DiTella, Annelies J. Heidekamp, and Ann T. Lemley, Cornell Cooperative Extension, College of Human Ecology, Fact Sheet 12, Nov 1999, Updated Jan 2006.