Following any disaster, manmade or natural, safe water and proper sanitation are of vital importance. In the case of natural disasters, water sources can be contaminated or altogether destroyed. Waste can also enter the water source, rendering it poisonous to anyone who drinks it. Earthquakes, tsunamis and hurricanes can destroy the infrastructure necessary to keep safe water flowing and can even cause water sources to disappear completely.

Water sources can also be compromised in the case of man-made disasters, such as warfare, famine or politics. People caught in the midst of war, or living in refugee camps, are extremely susceptible to disease due to living in close quarters and inadequate sanitation.