Many special considerations are needed in the application of enzymes to contaminated drinking water systems. Because of the large volumes of water contained in water distribution and treatment systems, a decontaminant will need to be active for a much longer time than in military operations. As drinking water flows very quickly in pipes, methods need to be developed to ensure that the enzymes maintain sufficient contact with the contaminated water or materials. The goal of this project is to identify, develop, and evaluate at least one enzyme-based method for treating flowing contaminated water and one enzyme-based method for decontaminating drinking water pipes. A thorough literature search was undertaken to fully identify the potential of enzymes to treat contaminated drinking water and/or to decontaminate distribution systems equipment. The literature search considered the potential application of enzymes to a large range of possible water contamination scenarios, from groundwater to drinking water and from toxic industrial chemicals to chemical and biological warfare agents.