Using the Multi-Criteria AHP for the Optimal Selection of Site Location and Wastewater Collection System The Case Study of Varzeghan

This study investigates the use of multi-criteria decision making in waste management and selection of the site location and proper wastewater collection and processing system in Varzeqan Town. Moreover, the effect of the decision-making method employed on ranking the final alternatives will be evaluated. Different factors are involved in the selection of wastewater treatment construction sites. These factors, in turn, not only depend on the special location and time the decision is made but also have their own weights in the final decision. In this study, the environmental conditions in the study area are initially investigated to select one site from among five different alternatives proposed for the construction of the facility using the AHP method. Also, the AHP method is used to evaluate and select the suitable collection and treatment method from among the four non-conventional options including Septic Tank Effluent Gravity, Septic Tank Effluent Pressure, Vacuum Sewerage System, and Simplified Sewerage for this region based on the special geographical and geotechnical conditions. The results indicate that the barren lands between Varzeghan Town and Dizaj Safar Ali Village are the best site for constructing the treatment facility and that the simplified sewarge system is the best collection system for the region.