Modeling the Factors Affecting Sanitary System Condition Assessment in Egypt

In the most common cases, sanitation systems consist of four main phases: sewage networks, pump stations, force-main lines, and treatment plants. This research is dedicated to the systematic identification and hierarchical prioritization of crucial factors that impact the condition assessment of various stages within the sanitation system. An initial review compiled a comprehensive list of 115 factors from the literature that influence the condition assessment of the sanitation system’s distinct phases: 31 factors for sewer networks, 21 for pump stations, 18 for force-main lines, and 45 for wastewater treatment plants. By administering 88 detailed questionnaires to field experts, these factors were distilled to 59, predicated on their ascribed importance indices. Factors that achieved an importance index above the 50% threshold were considered to be significant and were retained for in-depth analysis, whereas those with an index below 50% were excluded from the prioritization process. The analytic hierarchy process (AHP) was used to compare and rank these factors. The results indicated that the two most important factors affecting the condition assessment of sewage networks are pipe material for sewers and cover and frame for manholes, respectively. The factors for pump stations are operational and maintenance procedures for pumps and protective measures for receiving wells, respectively. Pipe material, operation pressure, and corrosion of valves of mechanical pieces are the important factors for force-main lines. The age of electromechanical equipment and cavitations are the two most important factors affecting the condition assessment of wastewater treatment plants. A heuristic evaluation of three existing case studies was used to validate the model, and resulted in correlation coefficients ranging between 0.801 and 0.871. This study will support decision makers in managing sanitation system assets.