Fuzzy-Based Methodology for Risk Assessment in Water Treatment Plants

This research examines the reasons for water treatment plants failure based on the analysis utilizing fault tree analysis. Qualitative analysis was used to achieve 33 basic events that lead to 12 minimal sets of fault tree analysis data representing the minimum plant failure probability. There is a great probability that 1 of the 12 minimal sets from the fault tree analysis will causes problems and failures in the fundamental operation of the facility. The research suggests a new method combining diverse experts with a range of theories to assess the probability of events in order to avoid the problem of lack of precision that will be faced when assessing the basic events. The proposed method was applied on the Sixth of October Water Treatment Plant as a case study. The data are used to determine the likelihood of a fault tree. Probabilities of the top event (TE) and the basic events (BEs) are calculated using Boolean relationships. The occurrence probability of TE is 15.6% per year. After ranking all risks, the researchers find that the most critical risk based on the probabilities of basic events is the failure of the electrical system, which has a high probability (0.037) with a high impact in the occurrence of failure. The proposed method describes the importance of using the measures in the sensitivity analysis of water treatment plants.