Ultraviolet-chlorine advanced oxidation processes (UV/Cl-AOP) are gaining attention, particularly in potable reuse applications. There is also potential for their use in the control of taste and odor and other contaminants in conventional drinking water treatment. There is no one comprehensive location containing information on UV/Cl, making it difficult for end users to identify key issues that must be addressed when considering UV/Cl, and the important questions to ask of technology manufacturers. The goal of this project is to consolidate information about the state of the art of UV/Cl-AOP in a single reference applicable to utilities, non-expert consultants, and regulators. The project will report on the basic science of UV/Cl-AOP, as well as highlight practical issues related to its implementation and operation. Research partner: California State Water Resources Control Board.