The deterioration of water quality can adversely affect consumers' health as well as the aesthetic properties of water (taste, odour, colour). To date, little consideration has been given to the impact of deteriorating (ageing) water mains on water quality as a major decision driver for the renewal/rehabilitation of water mains. The main objective of this research was to identify major deterioration mechanisms in distribution networks that may contribute to water quality failures (WQF) and develop a model to quantify overall potential for WQF as a function of this deterioration. Numerous factors affect water quality in the distribution network and interactions among them are complex and often not well understood. Water quality failures in distribution networks are relatively scarce, which makes it difficult to establish statistically significant generalizations. In such data-sparse circumstances, expert knowledge and judgement can serve as a supplement or even as alternative source(s) of information. This paper discusses major deterioration mechanisms that may contribute to WQFs in distribution networks, and proposes a modelling framework using fuzzy-based methods. The following two papers in this series will provide a mathematical formulation of the proposed model and its application using two case studies, respectively.
Keywords: distribution networks, fuzzy-based methods, potential for water quality failure, water quality models