Which of the following is a common method for disinfecting water supply systems?

Chlorination is a widely used method for disinfecting water supply systems due to its effectiveness in killing a broad spectrum of pathogens, including bacteria, viruses, and protozoa. The process involves adding chlorine or chlorine compounds to water, which react with microorganisms and create a disinfecting effect. Chlorination is favored in many municipal water systems because it not only disinfects the water at the time of treatment but also continues to provide residual disinfection as water travels through the distribution system. This residual effect helps to protect against potential contamination that could occur after initial treatment.

While boiling water is effective for disinfection, it may not be practical for large-scale water supply systems. Filtration can remove particulates and some pathogens but does not provide the same level of disinfection as chlorination. Ultraviolet light is a method that can effectively disinfect water by inactivating microorganisms, but it requires clear water and does not provide residual protection like chlorination. Therefore, chlorination stands out as a common and practical choice for ensuring the safety of public water supplies against a wide range of contaminants.