Abstract

This paper explains the principle of chlorination and reveals the free chlorine residual content within a drinking water distribution system located in peninsular Malaysia. The study found that the free chlorine at user points was slightly greater than 0.3 mg/l, which is higher than the WHO standard at 0.2 - 0.3 mg/l. Despite that it was not a guarantee to lower the level of the microbial since the results showed that the total coliform count was higher than the level suggested by Malaysian Water Association. Therefore, the tap water at the in-take point cannot be used for direct consumption but additional treatments such as filtration and boiling are required.

Key words: Drinking water distribution system, free chlorine residual, coliform.