David Thompson, age 9, of Anderson, S.C., for his question:
What does water pollution mean?
WE borrowed our big word pollution from the Romans of old who spoke Latin. Their word was borrowed from the Greeks who came before them. The olden words meant to make something dirty or unclean. Our word pollution is the act of making something dirty or unclean.
Polluted water is unfit for human use and is most likely unfit for animals. Some polluted water is harmful even to plants. The purest water in the world can become polluted and useless. Pollution occurs when decaying plants and animals or filth and sewage wastes are added to clean water. It also happens when strong acids and other dangerous chemicals are dumped into our seas and streams.
Water pollution is a big problem of our times, and there are reasons why. Our population is growing and more people need pure water. More new things are invented and more factories are needed to make them. The factories find new and still newer ways to do their work. These operations often use strong chemicals or produce troublesome waste materials. This overflow of dangerous factory wastes may cause water pollution. Dirty water from the bathtub and the laundry, toilet wastes and some of the garbage from our homes are sent down the drains. Factory waste materials also are carried away in streams of drain water. This used water is called sewage, and Every wide awake city has a well run sewage system to dispose of the sewage from homes and factories. The government has laws to see that the job is well done.
Most sewage water must be drained away to a nearby lake or river or to the sea, but first it must be c1eaned and treated. The chunky lumps are sifted out by screens. Sometimes chemicals are added to make them sett1e on the bottom. Filters, sprinklers and sludge tanks are used to help bacteria break up dusty fragments and decay. Chlorine is added to kill the germs. This sewage treatment removes most of the danger.
Some of our streams become frothy with detergents dump Ed by the sewage system. Experts watch for such chemicals and make plans to stop them from polluting our water supplies. In time, nature purifies our dirty water, but her work is too slow to keep pace with us. So we enforce strict rules and regulations to stop our sewage from polluting nature's water supplies.
Life in our world would end without a plentiful supply of clean water. The plant world thrives on water, and if you weigh 90 pounds, 30 pounds of your body is made from water. Nature uses a half ton of water to create 1 pound of food. You may use 50 gallons for your daily washing, drinking and cooking, and the factories may use more than 50,000 tons of water to make the family car.