Ozone destroys all the water borne pathogens and also helps reducing some of the organics present in the water. Another advantage of ozone is that it leaves no residual disinfectant so water is free from any form of toxicity.
UV light system
Ultraviolet light water treatment systems are commonly used to further improve the quality of filtered drinking water. UV light treatment consists of passing water by an ultraviolet light source, which eliminates any biological contamination in the water.