We will discuss about the Earth’s water. We know about three-fourths of the Earth’s surface is covered with water. It is present in oceans, seas, rivers, lakes and ponds. It is also present under the Earth’s surface as ground water. Water is very important for life. All living things need water to live.
Most of the water available on the Earth cannot be used by us for drinking. The water in seas and oceans is salty. At most places, the water in rivers and lakes is not clean enough to drink. It contains dirt and germs. It is said to be polluted water. Water gets polluted because wastes from our houses and factories are allowed to flow into rivers and lakes.
Polluted water has dirt and germs in it. Drinking polluted water can cause several diseases. Dirt and germs have to be removed to make the water fit for drinking. Water from a river or lake is pumped into the waterworks in the city. Here it is passed through filters to remove dirt.
Special substances such as bleaching powder are added to kill germs. The clean water is then pumped into our homes. Clean water is very precious. It should not be wasted.