What is the acceptable level of chlorine residual in a distribution system for effective disinfection?

What is the acceptable level of chlorine residual in a distribution system for effective disinfection?

• A. 0.2 mg/L
• B. 0.5 mg/L
• C. 1.0 mg/L
• D. 1.5 mg/L

Answer: (C)

The acceptable level of chlorine residual in a water distribution system for effective disinfection is commonly set at 1.0 mg/L. This concentration strikes a balance between sufficient disinfection capacity to eliminate harmful microorganisms and minimizing potential negative effects, such as taste and odor that can become more pronounced at higher concentrations. Chlorine is a widely used disinfectant due to its effectiveness, and maintaining a residual level of chlorine in the distribution system is critical. A level of 1.0 mg/L is generally recognized by regulatory agencies as effective for maintaining water quality throughout the distribution network while ensuring that the water remains safe for consumption. Inadequate levels, such as 0.2 mg/L or 0.5 mg/L, may not provide sufficient disinfection, potentially allowing pathogens to survive in the water. Levels higher than 1.0 mg/L, such as 1.5 mg/L, might lead to undesirable taste and could cause more significant issues related to customer acceptance of drinking water.

The acceptable level of chlorine residual in a water distribution system for effective disinfection is commonly set at 1.0 mg/L. This concentration strikes a balance between sufficient disinfection capacity to eliminate harmful microorganisms and minimizing potential negative effects, such as taste and odor that can become more pronounced at higher concentrations.

Chlorine is a widely used disinfectant due to its effectiveness, and maintaining a residual level of chlorine in the distribution system is critical. A level of 1.0 mg/L is generally recognized by regulatory agencies as effective for maintaining water quality throughout the distribution network while ensuring that the water remains safe for consumption.

Inadequate levels, such as 0.2 mg/L or 0.5 mg/L, may not provide sufficient disinfection, potentially allowing pathogens to survive in the water. Levels higher than 1.0 mg/L, such as 1.5 mg/L, might lead to undesirable taste and could cause more significant issues related to customer acceptance of drinking water.