Slug Feed Optimal Disinfection of Water Distribution Networks Following a Contamination Event

Water distribution systems are vulnerable of being intentionally or accidentally contaminated. In the case of a contamination event the contaminated section of the water distribution system should be located, isolated, and cleaned before it can be returned to regular service. Depending on the specific contaminant, the cleaning process mainly includes flushing and disinfection. All of the disinfection methods (e.g., tablet, continuous, and slug) require that the disinfectants will have minimal contact time (T) in a predefined concentration (C) with the pipes and the system’s apparatuses. The regulatory agencies, such as the Ministry of Health in Israel or the American Water Work Association, publishes procedures for the disinfection of water systems in which usually only a single water main is considered and no specific procedures are given for larger portions of the water system. This paper presents an optimal operation plan for the disinfection of water distribution systems using the slug feed method while considering the locations where the disinfectants should be injected into the network, injection times, flow rates, and drainage locations. The method is a two stage GA-EPANET procedure. It is demonstrated on a small real-world network section.