What is the purpose of maintaining a chlorine residual in treated water?

What is the purpose of maintaining a chlorine residual in treated water?

• A. To remove turbidity over time
• B. To prevent bacterial regrowth
• C. To enhance the taste of water
• D. To soften the water

Answer: (B)

Maintaining a chlorine residual in treated water is primarily meant to prevent bacterial regrowth. Chlorine is a powerful disinfectant that effectively kills or inactivates bacteria and other pathogens in drinking water during the treatment process. However, as water travels through the distribution system, there is a risk that bacteria can re-enter the water or that some surviving microorganisms can multiply if there are suitable conditions. By maintaining a chlorine residual, water utilities ensure that a consistent level of chlorine remains in the water after treatment, continuing to inhibit microbial growth and thereby protecting public health throughout the distribution process. In this context, the other options address different water quality parameters but do not accurately represent the primary function of chlorine residual. Turbidity is typically removed through filtration processes rather than residual chlorine. Enhancing the taste of water is not a direct purpose of chlorine, although some people may perceive a 'cleaner' taste with chlorinated water. Softening water involves the removal of hardness ions like calcium and magnesium, which is unrelated to the disinfection role of chlorine. Thus, the correct answer focuses on the essential role of chlorine in maintaining safe drinking water by preventing the growth of harmful microorganisms.

Maintaining a chlorine residual in treated water is primarily meant to prevent bacterial regrowth. Chlorine is a powerful disinfectant that effectively kills or inactivates bacteria and other pathogens in drinking water during the treatment process. However, as water travels through the distribution system, there is a risk that bacteria can re-enter the water or that some surviving microorganisms can multiply if there are suitable conditions. By maintaining a chlorine residual, water utilities ensure that a consistent level of chlorine remains in the water after treatment, continuing to inhibit microbial growth and thereby protecting public health throughout the distribution process.

In this context, the other options address different water quality parameters but do not accurately represent the primary function of chlorine residual. Turbidity is typically removed through filtration processes rather than residual chlorine. Enhancing the taste of water is not a direct purpose of chlorine, although some people may perceive a 'cleaner' taste with chlorinated water. Softening water involves the removal of hardness ions like calcium and magnesium, which is unrelated to the disinfection role of chlorine. Thus, the correct answer focuses on the essential role of chlorine in maintaining safe drinking water by preventing the growth of harmful microorganisms.