Each 30-gallon water barrel provides enough water for drinking, cooking, and light personal sanitation for two people. This provides the minimum supply of emergency water for two weeks (a gallon per person per day). A person can live for weeks without food, but without water your body can experience significant damage in a matter of days. That is why, in an emergency, water may be (besides your family) the most important item to have available. Made from Heavy-duty, thick, high-molecular-weight polyethylene resin. FDA-approved and BPA-free. The dark blue color of this 30-gallon barrel restricts light and helps control growth of harmful algae and bacteria.