Question

1. How much chlorine residual should be present at the consumer end.
2. What quantity of alum in kg is required to treat 2mg(million imperial gallons) of raw water, if alum dosing rate is given as 30ppm. 1 imperial gallon is equal to 4. 55 litres

Answer 1

1) For normal domestic use, residual chlorine levels at the point where the consumer collects water should be between 0.2 and 0.5 mg/l.

2) Quantity of Alum =0.89Kg