What should be the sump capacity ?

The sump capacity will depend on several aspects , like availability of water , number of persons residing in the building and will also depend on per capita demand per day . The size of the sump for a residence of four can start from 6000 litres capacity and may increase with increase in number of people. A person on an average uses 135 litres of water per day and this has to be multiplied with number of persons which will give us the total needed sump capacity per day