Disinfection methods include chlorination, pasteurization, ultraviolet light and boiling. The most common, oldest and relatively inexpensive method used to disinfect water is chlorination. Chlorine, an oxidizing agent, kills most bacteria and some viruses. In the proper concentrations and under adequate exposure time, chlorine is an excellent disinfectant. However, care must be taken to assure only clean, clear water is used.
Chlorine reacts with certain metals and organic matter in the water.
Using an activated carbon filter after chlorination will remove excess chlorine and limited amounts of chlorinated chemicals formed. Chlorination may also oxidize and remove some color and odor-causing substances including some iron and hydrogen sulfide. The chemical feed pump requires frequent maintenance. The chemical reservoir must be kept filled and the pump checked at regular intervals for worn parts. With pasteurization, water is heated to kill bacteria, viruses, cysts and worms.