Consequences Management of Chemical Intrusions in Urban Water Distribution Networks Using the Ant Colony Optimization Algorithm

Deliberate chemical contaminant injection is one of the most important dangers which threatens urban water distribution networks. Decisions made following the detection of such contaminant attacks are affected by complicated conditions. A variety of optimal operational measures and strategies must be adopted to safeguard the public health which may include isolation of the contaminated area through valve operations for pollution containment, public alarms, and flushing of the polluted water out of the system through hydrants or pumps. In this study, consequence management of chemical intrusions using the above strategies is investigated with two main minimizing the number of polluted nodes and minimizing the operational activities while minimizing "the recovery time of the network to normal conditions" is also considered as a novel objective. The problem is treated as both a single- and a multi-objective optimization problem in which the Ant Colony Optimization Algorithm is used for the first time. One of the most important achievements of this study is the substantial role of pumps in consequence management of such attacks.