What is the purpose of a Chlorine residual in water systems?

• A. To enhance flavor
• B. To eliminate heavy metals
• C. To kill bacteria that might enter later
• D. To improve clarity of water

Answer: (C)

The purpose of chlorine residual in water systems primarily concerns its role in disinfection. Chlorine is widely used as a disinfectant to destroy harmful microorganisms, including bacteria, viruses, and protozoa that can compromise water safety. Maintaining a chlorine residual in the distribution system ensures that any potential contaminants introduced after the initial treatment are effectively eliminated, thus providing a continuous safeguard against biological hazards.

While chlorine can influence the taste of water and may have some interaction with metals and clarity, these are not the primary objectives of maintaining chlorine residual. Instead, the focus is on ensuring that a sufficient concentration of chlorine is present to protect public health by inhibiting the growth of pathogens that may enter the water supply at various points after treatment.