As the quality of water can be seriously affected by a disaster or an emergency, it is best practice to disinfect all emergency water supplies. The most common way of disinfecting is with chlorine. This technical note explains why disinfection is important, why chlorine is used, how it works, how to test for its presence and where and when to test.
REED, B. (2011): Measuring Chlorine Levels in Water Supplies. Technical Notes on WASH in Emergencies #11. Leicestershire: Water, Engineering and Development Centre (WEDC) URL [Accessed: 11.03.2019] PDF