Be sure that the water you are treating is drinking-quality water to begin with. To treat water for storage, use liquid household chlorine bleach that contains 5.25 percent sodium hypochlorite. Do not use bleach with soaps or scents added. Add the bleach according to the table below, using a clean, uncontaminated medicine dropper.

• 4 drops bleach per quart or liter container of water
• 8 drops bleach per 2-quart, 2-liter, or ½ gallon container of water
• 16 drops bleach, or 1/4 teaspoon, per gallon or 4-liter container of water

When treating larger quantities of water, use the following table to convert drops to standard measuring units.

• 8 drops = 1/8 teaspoon
• 16 drops = 1/4 teaspoon
• 32 drops = 1/2 teaspoon
• 64 drops = 1 teaspoon
• 192 drops = 1 tablespoon
• 384 drops = 1/8 cup which is equal to 2 tablespoons

Stir the water and allow it to stand for 30 minutes. Chlorine should be detectable by odor after the 30 minute waiting period. If the water does not smell like chlorine at that point, repeat the dose and let it stand another 15 minutes.

Place caps on containers and attach labels describing the contents and when each was prepared.

Water stored in metal containers should not be treated, prior to storage, with chlorine since the chlorine compound is corrosive to most metals. Therefore, only very pure water should be stored in metal containers.