Food and shelter are crucial for living, but nobody can survive for very long without water. That’s why, since the beginning of history, civilizations have lived near abundant sources of H20.
But it’s not enough just to have plenty of it. The same water that gives life can also make people sick or even kill them, if it contains dangerous substances or disease-causing microbes. And since people use water for activities such as irrigating crops, washing and waste disposal, sources of water close to a human population can easily become contaminated. Read more