Last updated: 12 Jun 2018


Source: Givewell's Intervention Report

Water quality interventions aim to improve the quality of water by removing or disabling the pathogens found in water, usually through one of the following methods:

   • Chemical treatment, most commonly with chlorine

   • Physical removal of pathogens, such as filtration, absorption or sedimentation

   • Heat or UV disinfection, such as boiling or sun exposure

   • Protection from recontamination, through, for example, piped distribution and safe storage


Source: Safe Drinking Water Foundation's Factsheet

Chlorination is a chemical disinfection method that uses various types of chlorine or chlorine-containing substances for the oxidation and disinfection of what will be the potable water source.

Chlorination can be done at any time/point throughout the water treatment process - there is not one specific time when chlorine must be added. Each point of chlorine application will subsequently control a different water contaminant concern, thus offering a complete spectrum of treatment from the time the water enters the treatment facility to the time it leaves.

Although chlorination does have some drawbacks (it has shown to be effective for killing bacteria and viruses, but not for some protozoan cysts), it continues to be the most popular, dependable, and cost-effective method of water disinfection.