Evaluating Water Quality Failure Potential in Water Distribution Systems: A Fuzzy-TOPSIS-OWA-based Methodology

Abstract

The goal of a water distribution system (WDS) is to deliver safe water with desirable quality, quantity and continuity to the consumers. In some cases, a WDS fails to deliver safe water due to the compromise/ failure of water quality which may have devastating consequences. The frequency and consequence of a water quality failure (WQF) can be reduced if prognostic analysis and necessary remedial measures are taken on time. This study developed a prognostic model to predict WQF potential in a WDS. The study identifies important factors (parameters) which can directly and/or indirectly linked to WQFs. These factors are classified into two groups—the causes of WQF such as lack of free residual chlorine, or excess of total organic carbon, and the symptoms of WQF such as taste & odor, color which are in fact the effects of certain causes of WQF. The interrelationships among the symptoms and the causes have been established based on extensive literature review and elicited expert opinion. A fuzzy-TOPSIS-OWA-based model has been developed to identify the impacts of different influencing parameters on the overall WQF potential. The developed model has been implemented for a WDS in Quebec City (Canada). To study the impacts of uncertainties of the influencing factors, a Monte Carlo simulation-based sensitivity analysis has been carried out. It is anticipated that the developed model can help water utilities to understand the role of different factors on WQF.