The objective of this project is to conduct research on a novel water treatment process that offers promise in accomplishing a disinfection effect without producing halogenated hydrocarbons which have been determined to be carcinorganic. The project involves determination of the ability of selected chemical nucleophiles, especially sulfites to decompose mutagenic or carcinogenic chlorination byproducts, to evaluate the degree to which additional chlorination byproducts form upon rechlorination following electrophilic decomposition, and to identify some of the degradation products of these halogenated compounds. The identification and recovery of specific compounds will be achieved by liquid/liquid extraction and closed loop stripping in conjunction with gas chromatography and mass spectrometry. Such information will be combined with health-effects data from on-going research elsewhere to provide an overall evaluation of the potential of nucleophilic decomposition for drinking water treatment. This research may lead to the development of a full-scale application of nucleophiles in the form of dechlorinating agents or anionic resins. The single most significant contribution of drinking water treatment to public health in the US has been the widespread use of chlorination. Since its general acceptance in the US in the early part of this century, water borne diseases have been effectively controlled, and in some cases virtually eliminated. Now, concerns over organic chlorination byproducts are threatening to remove chlorination from consideration for many raw waters. This research may lead to concepts that will continue to permit use of chlorine for disinfection without production of potentially harmful by products.