Water purification

Methods were discovered for keeping water pure and safe. Septic tank, cesspool, and other equipments for taking care of waste were placed away so they couldn’t possibly drain into water supplies.

But germ still got into the water in other ways. Today water is treated in various ways to kill any germs that might be in it. Usually this is done with a chemical called chlorine. Only small amounts of chlorine are used, but sometimes its odor can be detected when water is run from the faucet.

In places where water is treated and purified, typhoid fever and other diseases spread by water have almost disappeared. When there are floods, the water purifying system may be overloaded and become ineffective. When this happened, people are usually told to boil water before drinking it, to make sure that all germs are killed.

In some parts of the world the water is not purified and can’t be trusted. Soldiers serving in such places use special chemicals to purify small amounts of water for drinking. Designing and constructing safe water supplies is an important job of scientist who are trying to improve health conditions in underdeveloped countries.