In order to meet basic needs for drinking, cooking and washing, the recommended allowance is two gallons per person per day. Authorities further advise to allow for pets' needs also. It is not safe to use containers that have held toxic substances. Seal and label the bottles before storing in a cool, dark place. Water should be replaced every three months.
Places suited for additional storage at the last minute are the bath tub, washing machine and sinks.
Hidden sources for emergency supplies include the hot water tank, ice cubes and the plumbing. Use your emergency supply or boil tap water before drinking until authorities indicate that water is safe to drink. Sterilize tap water by boiling or purify with chemicals. Boil all well water before use. Boiled or stored water tastes better if you put oxygen back into it by pouring back and forth between containers.