MUTAGENICITY OF DRINKING-WATER FOLLOWING DISINFECTION

Many drinking water utilities in the USA are considering alternatives to chlorine for disinfection in order to comply with federal regulatio ns regarding disinfection by-products. An evaluation is thus needed of the potential risks associated with the use of alternative disinfecta nts relative to those posed by chlorine. Two pilot-scale drinking wate r plant studies were conducted using a variety of disinfection schemes , incorporating ozone, monochloramine, chlorine dioxide, and chlorine. Concentrates of these water samples were tested, using the Ames Salmo nella assay, in order to compare the relative mutagenic potencies of t he water samples following the different methods of disinfection.