AWWA JAW71381

Recent years have seen the introduction of a variety of early warning systems designed for continuous on-line detection of disruptions in security and quality in the water distribution network. Any evaluation of these systems must take into account numerous factors that go beyond detection capability to include such criteria as ease of use and dual-use value. This article proposes standard criteria for the coverage, operational, and performance characteristics of early warning systems and describes a methodology for mathematically evaluating these systems using a modified receiver operating characteristic (ROC) curve widely used by the military. The combination of extensive specific criteria and the use of the modified ROC curve can help water utilities in selecting appropriate and effective early warning system technology. In addition, the modified ROC curves can be used during system operation to help operators set realistic detection thresholds based on risk conditions while understanding the potential tradeoff in false alarms. Includes 10 references, tables, figures.