Integrated fuzzy logic and multicriteria decision model methods for selecting suitable sites for wastewater treatment plant: A case study in the center of Basrah, Iraq

Abstract

In environmental infrastructure projects, decision-making can be complex and challenging because of the inherent trade-offs between environmental, economic, and social considerations. During urban development, wastewater treatment plant (WWTP) site selection is one of the most critical parts of environmental infrastructure. Choosing suitable sites for constructing a WWTP is based on various variables and limits. In the modeling phase of this study, ten criteria were developed from three main criteria to evaluate sites suitable for WWTPs. These criteria were slope, soil type, and proximity from rivers, roads, agricultural lands, railways, oil fields, groundwater, outfall, and residential areas. These parameters and their respective weights were determined based on a literature review, expert knowledge, field observation, and geophysical investigation. The fuzzy analytical hierarchy process (AHP) method, which integrates AHP and fuzzy logic, was used as a multicriteria decision-making, and fuzzy membership functions were performed to determine the criteria weights used with geographical information systems to select all available sites for the WWTP for the center of the Basrah province. The study concludes that the old Hamdan WWTP was located in an unsuitable area. In light of the rapid population growth in Basrah center in recent years, it may be proposed that a new WWTP be built in a new location that meets environmental, economic, and social criteria. This study reveals that 138.52 km2 (or 9.98% of the total land area) is appropriate for constructing the new WWTP.