What is the primary purpose of disinfection in drinking water treatment?

• A. Kill or inactivate pathogens to prevent disease transmission.
• B. Remove dissolved minerals to improve taste.
• C. Remove all organic matter by chemical precipitation.
• D. Add nutrients to water.

Answer: (A)

Disinfection is about protecting public health by killing or inactivating pathogens in the water so people don’t get sick from drinking or using it. After other treatment steps remove solids and improve taste and clarity, disinfection provides a final barrier against microorganisms such as bacteria, viruses, and protozoa that could slip through. It’s typically done with sanitizing agents like chlorine, chloramines, ozone, or UV light, and a residual disinfectant in the distribution system helps prevent any remaining microbes from growing as water travels to consumers. The other options describe removing minerals for taste, removing all organic matter by chemical precipitation, or adding nutrients, which aren’t the goals of disinfection.