“Purifying and Storing Water,” Ensign, Oct. 1991, 71
Water is more essential in sustaining life than food is, so it is one of the first items you should collect for your food storage. Although it is difficult and impractical to store water in large quantities, experts recommend that you keep a two-week emergency supply of water on hand, because natural disasters such as floods or earthquakes may pollute or disrupt water supplies for that long. You should store at least fourteen gallons per person—seven for drinking and seven for other uses.
Before You Store
If your water is free of bacteria and if you keep it in clean, tightly closed containers away from sunlight, it will remain safe indefinitely. To purify your water before storing it, add:
Household bleach—Any household bleach solution that contains hypochlorite, a chlorine compound, as its only active ingredient will purify water easily and inexpensively. Add two drops of bleach for each quart of clear water, four drops per quart if the water is cloudy. Thoroughly shake or stir the bleach into the water.
Allow the mixture to stand for thirty minutes. Water should still have a distinct taste or smell of chlorine; if it doesn’t, add another dose of bleach to the water and allow it to stand another fifteen minutes. The taste and/or smell of chlorine in the water is a sign of safety. If you cannot detect the chlorine, do not store the water. The chlorine solution may be weakened through age or for some other reason.
Iodine—You can purify small quantities of water with ordinary 2 percent tincture of iodine. Add three drops to each quart of clear water, six drops for cloudy water. Stir thoroughly.
Like bleach, iodine becomes weaker over time and may not purify the water. Rotate your iodine each year to ensure that it will work when you need it.
Good water-storage containers are airtight, breakage resistant, and heavy enough to hold water. They should stack well and have a lining that won’t rust or affect the flavor of the water. The following containers meet these criteria:
Mylar bags in a box.
Heavy plastic or fiberglass drums. These should be food-grade drums.
Metal tanks, if they are lined with fiberglass.
Water heaters that are glass-lined. Drain your heater periodically to release any accumulated sediment so that you can use the full capacity. Learn how to close your heater’s inlet valve so that you can shut it immediately after the water supply is disrupted. This will prevent contamination.
Water beds. A double bed holds about two hundred gallons of water. You can use this water for non-drinking purposes, but if you do, you must use an algicide that is food-approved. Some are poisonous.
Bleach bottles. These are not appropriate for storing water for drinking or cooking, but are good for storing water for other uses.
Using Your Water
If you have had water in storage for a long time or if it is contaminated, you can purify it by one of the following methods:
Filtration. There are many good water filters on the market. The activated charcoal type is best because it can also remove some bad tastes. Some filters also add chemicals to kill bacteria.
Chemicals. In addition to the bleach and iodine treatments described above, halazone tablets are effective and readily available. However, they have a shelf life of only one year. Most outdoor stores have other good treatment chemicals as well.
Boiling. Boil water for three to five minutes, depending on elevation. A higher elevation requires longer boiling.
For added protection, store a supply of water-purifying agents.—Relief Society General Board