Storage of Emergency Water – Various sources recommend home storage of a two week supply of water. The amount often recommended is seven gallons per person for drinking and food preparation, and another seven gallons per person for other limited uses such as hand washing, teeth brushing and dish washing (total fourteen gallons per person for two weeks). Both glass and plastic containers are commonly used for water storage at home. Containers should be clean and sanitary.
Glass containers are breakable and somewhat heavy compared to plastic, but they are not permeable to vapors and gases, the amount of leaching (dissolving) of chemicals from glass into water is insignificant. Plastic containers are lightweight and substantially more resistant to breakage than glass. If plastic containers are used, care should be taken to assure that they are made of plastic approved for food contact by the Federal Food and Drug Administration. Polyethylene plastic is approved for food contact and is commonly used for containers of various sizes, including 55-gallon drums.
Certain types of plastic containers are not intended for food contact (such as vinyl plastic waterbeds, or trash containers) and may leach undesirable chemicals into stored water. Leaching of chemicals from approved plastics is negligible. For long-term storage, water should be sterilized or disinfected. Water stored in thoroughly cleaned plastic or glass containers can be chemically disinfected for long-term storage by treating each gallon with sixteen drops of liquid chlorine bleach (Clorox or Purex type bleaches, containing 4% to 6% sodium hypochlorite). One teaspoon of bleach disinfects five gallons of water. This level of treatment will prevent growth of microorganisms during storage.
Water stored in plastic containers should not be stored near gasoline, kerosene, pesticides or similar substances. Vapors from these substances could permeate the plastic and affect the water. Thick-walled polyethylene containers are significantly less permeable to vapors than are thin walled containers, Be certain, when selecting a storage container for water, that it has a tight fitting cap or lid to prevent entrance of contaminants and evaporation of water. Because sunlight has an adverse affect on plastic, water should be stored away from direct exposure to sunlight.