Monitoring water quality in water supply and distribution systems

Various reasons mandate nowadays the use of automated systems for monitoring remotely, and in a continuous fashion, the quality of (drinking) water in supply aqueducts (conveying water from reservoirs to treatment facilities) and in pipe distribution networks. Natural disasters and terrorist actions also provoke us with serious challenges regarding the vulnerability of these supply and distribution systems and have become an issue for further consideration by those in charge of their operation and maintenance. The quality of drinking water maybe monitored by observing simultaneously several quality indices (from the parameters included in the E.E. regulations) at various sites of these water-conveying systems. This paper describes an integrated methodology for realizing such a monitoring. It also presents some criteria for selecting the observed indices and determining both the geographic distribution and density of the monitoring sites where collection, and transmission to a respective central control-and-command station, of the observed water quality characteristics is conducted. The monitoring systems are complemented by a small number of mobile units that perform occasional, in situ, quick chemical analyses for validating the performance of the continuously observing sensors at the various terminal or other site stations. At the respective central station, the data are either analyzed to produce index levels on a daily basis or used, via assimilation schemes, in conjunction with software that simulate the water quality in the entire supply and distribution networks to further provide a realistic picture of the water quality across the latter. The advantages of this integrated monitoring methodology are enumerated and its capabilities to provide early warnings with regard to extreme events are compared with the (limited) capabilities of other systems that have appeared in the recent literature.