Minimizing the Adverse Effects of Contaminant Propagation in Water Distribution Networks Considering the Pressure-Driven Analysis Method

Abstract

Contaminant intrusion into water distribution networks can have disastrous consequences. This event poses a threat to public health and could result in political instability and social problems. After the contaminant and its source are detected, the main issues are consequences management and contaminant withdrawal from the water distribution network. To do this, several actions are required, including containing contaminant spread by closing valves and opening hydrants to flush out the polluted water. These actions may lead the network to a critical state in which the pressure of some nodes falls below the standard measure. In these network conditions, a pressure driven analysis of the water distribution network would be necessary. In this study, a combination of hydraulic simulation based on pressure driven analysis and particle swarm optimization is used to minimize the negative effects of contaminated water on public health as an immediate response after the contaminant entrance into water is detected. Based on the type of contaminant, two different emergency response strategies are introduced. Multiobjective optimization is performed when a nonharmful contaminant has entered the network. In this case, the main objectives are to minimize the impacts of contaminated water on consumers and the cost of operations. In another response strategy, reducing the time the network requires to return to a normal state is the objective of single-objective optimization when the contaminant is harmful. The proposed model was applied on the water distribution network of Sabzevar in northeastern Iran. The results proved the model’s credibility and its applicability in real water distribution networks, even in cases of contaminant intrusion.