In the chain of water distribution, the network is the most complex element to be analyzed and managed to deliver safe water to the users due to the vast dispersion of the potential contamination spots. In fact, water introduced into the water distribution network can be subjected to various types of contamination in the network itself like, endogenous or exogenous, either accidental and deliberative (terrorist attack or sabotage), phenomena. For this reason, some countries have already started research programs aimed at the development of an Online Water Quality Monitoring(OWQM) and Early Warning Systems (EWSs). Both of them are based on sensors installed in selected nodes of the network and are capable of quickly detecting contamination events. The implementation of EWSs opens new interesting research topics, with particular reference to the technological aspects, to the employment of expert systems for the interpretation of the detected data, and to the definition of modeling tools for the design and management of monitoring and alarm systems. Skryť popis