Available literature on the formation of halogenated organic compounds during the chlorination of water supplies has been reviewed critically. Types of organic compounds likely to be encountered in natural waters have been surveyed and various known or prospective reactions of dilute aqueous chlorine with these types of compounds have been discussed. It is concluded that two principal types of chlorination reaction are expected: (1) electrophilic aromatic chlorination as in the long-known formation of chlorophenols; and (2) electrophilic chlorine addition to activated double bonds like that of enolacetone. Chloroform or other haloforms may occur as end products of exhaustive chlorination in either case. General substitution reactions of chlorine are unlikely however. Possible methods for minimizing the concentrations of halogenated organic compounds in municipal supplies have been outlined. These include pretreatment methods, such as coagulation or preozonation to reduce amounts of precursors to the halogenated compounds, and posttreatment methods, such as carbon adsorption or aeration to remove halogenated compounds after their formation. Needed research has been described.

"Contract no. P5-01-1805-J ; program element 1CA046." "March 1975." Prepared for Office of Research and Development, U.S. Environmental Protection Agency. Includes bibliographical references (pages 43-54).