Which action is considered a step in treating a field water system?

• A. Potable water stored for use
• B. Water is heated
• C. Disinfectant added
• D. Water is transported to distribution network

Answer: (C)

Disinfection is the step that actually reduces microbial risk in a field water system by inactivating pathogens and leaving a residual that protects the water as it moves through pipes. Adding a disinfectant, such as chlorine or chloramine, is a standard treatment action because it directly lowers disease risk and helps maintain water quality throughout distribution.

Storing potable water is about having already treated water available for use, not a treatment action itself. Heating water isn’t a common field treatment step for large-scale potable systems, since it’s energy-intensive and impractical for treating large volumes. Transporting water to the distribution network is part of delivering finished water, not treating it.