3. Everyone in the world needs clean water. Water can carry substances such as soil, dirt and chemicals. We have to treat water so that it is safe for everyone to use.

4. Water is stored in a place called a reservoir.A reservoir is a place where water is stored before it is drunk by people.

5. It is treated in treatment factories. This involves lots of processes like filtration and disinfection.

6. Chlorine can be used as a gas or liquid for disinfect.Sodium carbonate is used to create flock.Aluminium Sulphate is used in coagulation lime is used for ph correction.