Decentralized Wastewater Treatment Plants Site Selection of Qom Province by Using Fuzzy Logic and AHP

Water pollution has received particular attention in recent years. One of its reasons can be water scarcity or drought. One of the methods which significantly helps to manage this crisis is reuse of the effluent of wastewater treatment plants. In big cities, wastewater is usually collected by an integrated wastewater collection system and then treated in a centralized wastewater treatment plant. This approach has a lot of limitations regarding wastewater collection costs, risks of unanticipated events and treated effluent reuse. Furthermore, in less populated cities, using centralized wastewater treatment plants might be costly when concerning infrastructural and operational costs. In this situation, it is recommended in the literature to use decentralized wastewater treatment plants (DWWTPs). Therefore, it is crucial to highlight and locate communities with more potential to use this facility. This study aims to locate the communities which have the most potential to construct DWWTPs and dedicate them a fuzzy-AHP index. Based on the findings of this study, the prioritized societies with high potential to build DWWTP in Qom Province are Sarm, Vanarch, Jandab, Varjan, and Kahak. Finally, the communities under the study were compared regarding wastewater collection system costs by using WPM model. The results indicated that DWWTP was multiple of times more economical than the centralized method.