organic chemicals such as chloroform that can form during water disinfection using chlorine-based chemicals. Their concentrations are regulated under the NPDWS.

Organic and inorganic compounds that often result from the reaction between a disinfectant and naturally occurring materials in water; chloroform is a commonly found example.

Halogenated organic chemicals formed when water is disinfected.

Pollutants formed when organic materials in a drinking water source react with the disinfectant, such as chlorine or ozone. Trihalomethanes (THMs) are a major group of disinfection byproducts.

Compounds created by the reaction of a disinfectant with organic compounds in water.