Many people use 30- and 55-gallon blue barrels for storing water. New barrels are preferred but if you buy a used one make sure it was used only for storing potable water, food, or beverages. The blue color is usually indicative of a food-grade container.
Used barrels may retain the smell or taste of the previous contents. Make sure it is a flavor you can live with in your water. Used barrels should be cleaned thoroughly with hot soapy water. Water can be heated by putting the partially filled barrel in the sun. When the water is hot, add detergent, put the lid on and roll the barrel around on the ground to wash all surfaces inside. A sponge can be attached to a long handle or dowel to rub the surfaces, if necessary. Dump out soapy water and rinse thoroughly with clean water.
Prepare the new or cleaned used barrel for storing water by pouring a gallon of bleach into the barrel. Put on the lid and roll the barrel around to coat all surfaces, including the top and bottom, with bleach. Dump out the bleach. Any remaining bleach will break down in the water over time.
Fill the barrel with clean, potable water using a food grade hose. Food grade hoses can be purchased where RV supplies are sold or from preparedness supply companies.
Water can be retrieved from the barrel with a pump made for water barrels. Some barrels have a spigot near the bottom and will not require a pump.
Water barrels are best stored inside and away from light. If they must be stored outside, cover the barrel as much as possible to minimize light exposure, to keep it clean, and to insulate it from heat and cold. If there is a risk of freezing, fill the barrel only 9/10 full to allow for expansion.
Barrels should not be stored directly on cement. Place a barrier, such as wood, between the barrel and the cement. Racks for either vertical or horizontal storage can also be purchased or built.
If you store water in large barrels, also store water in smaller containers that can be used in the house during storms or can be taken with you in an evacuation. They can be refilled from the barrels during a water outage.
If water barrels come in contact with flood waters, take care to clean them thoroughly. Dump out the water in them. Wash the outside with warm, soapy water and rinse with clean water. Scrub the outside with a brush and sanitizing solution of 1/4 cup (5-6% sodium hypochlorite) bleach per gallon of water (or 1 cup per 5 gallons)1 . Let the barrel air dry. Rinse out the inside and then pour in a gallon of bleach, put on the lid, and roll the barrel around to coat all surfaces. Dump out the bleach and refill with clean water using a food grade hose.
If water barrels are submerged in flood waters, consider discarding them.