Water systems are complex and difficult to characterize. It has become conventional wisdom that water quality can change significantly as water moves through a water system. This awareness has led to the development of water quality/hydraulic models which can be used to understand the factors that affect these changes and to track and predict water quality changes in drinking water networks. Recent events have focused the water industries attention on the issue of water system vulnerability and it is apparent that the most vulnerable portion of a water utility is the network itself. Therefore interest has grown rapidly in the potential use of water quality/hydraulic models for assessing water system security and for their potential for assisting in the protection of water systems from deliberate contamination by biological and chemical threat agents.
In order to use water quality/hydraulic models correctly there are two features that must be understood. These are the characterization of system demands and the proper calibration of these models using tracer tests. Recent research in both of these areas indicates that a better understanding of both of these aspects could substantially improve the use of models for system protection.
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