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area exposed to the sun. The water evaporates under the hot sun, leaving behind
layer of salt. In India you will find such salt farms in the coastal plains of Gujarat.

Clean drinking water
Is the water from your nearest source fit for drinking?
Water needs to be purified so that it is safe to drink.
Water that is suitable for drinking is called potable
water. Water from various sources is purified. First
water is allowed to stand so that the heavy par cles of
impuri es in it can se le down. This process is called
sedimenta on. Then it is passed through chemicals,
sand and gravel that act as filters, to remove the finer
par cles of impuri es. This process is called filtra on. A
small amount of chlorine is added to disinfect the water
and kill the germs present in it. This process is known as
chlorina on. The potable water is then stored in water
tanks. It is supplied to houses through pipes and taps.

Scarcity of water
Water is the necessity of life. We cannot survive without water. Yet, more than one-

third of people in the world do not have access to
clean water! The world popula on is growing and the
water is limited. This makes the problem even more
difficult. Drawing excess water from underground is
bringing down our water table. In the coastal area,
this prac ce some mes makes the groundwater
salty.

One solu on to this problem is rainwater harves ng.
Rainwater, the main source of water, can be conserved through rainwater harves ng.
Rainwater is collected tanks and passed through filters to remove impuri es. Then it is
stored and used for laundry and other ac vi es. Harvested rainwater recharges
groundwater. This technique helps to reduce scarcity.

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