(11f) Adsorption and Decontamination of Chemical and Biological Substances in Drinking Water Distribution Systems

There is a growing concern over the potential use of chemical and biological substances in an attempt to contaminate drinking water supplies. The fate of the chemical and biological agents in water are dependent on environmental conditions such as temperature, pH, conductivity, oxidant, ultraviolet light, and the presence of organic material. The U.S. EPA's Office of Research and Development's (ORD) National Homeland Security Research Center (NHSRC) is charged with determining ways to protect the nation's water supplies from a threat and preventing human exposure upon an attack. The treatability of contaminants in a water distribution system is needed to decontaminate a contaminated water system and maintaining safe drinking water throughout the water distribution and storage systems to the point of delivery to the consumer. In the event of an intentional contamination of drinking water, appropriate advice can be provided to federal, state, and local officials on decontamination procedures of water distribution systems. This advice may include variety of information, including whether the contaminant can be rinsed from the distribution system, concentrations and exposure time for effective decontamination agents.

This study evaluated the potential for contaminants to adhere to a variety of pipe materials commonly found in a water distribution system. Adherent combinations were tested to determine the selected chemicals acted as decontamination agents or physically removed the biological contaminants when added to the system. Wide spectrums of chemical and biological substances have been evaluated under this study. Decontamination of the water distribution system has been conducted to remove the contaminants from the interior surface so that the residual contaminant does not pose health or aesthetic problem.