Although several methods eliminate microorganisms and odors in water, chlorination is the most commonly used. Chlorination is effective against many pathogenic and non-pathogenic bacteria, but at normal dosage rates it does not kill all viruses, cysts, or worms. Often combined with filtration, chlorination is an excellent and cost-effective way to disinfect drinking water supplies, eliminate odors, and oxidize iron, and other metals.
Chlorine is a powerful disinfectant, able to kill bacteria, viruses, and many other microorganisms. This tactic has been used for over 100 years. Virtually all municipally treated water has chlorine added, often in a couple different phases of the treatment process. Although very effective for bacteria and viruses, there are some micro-organisms such as cryptosporidium and giardia that are not effectively destroyed by chlorination.