Comparison of Physical Sampling and Real-Time Monitoring Strategies for Designing a Contamination Warning System in a Drinking Water Distribution System

Protecting the water systems of the United States from terrorist attacks has become a federal and local priority. Routine sampling and analysis has been proposed as a potential monitoring approach that could be used to provide early detection of contamination events in drinking water systems. Using the threat ensemble vulnerability assessment computational framework, an evaluation of the benefits of three routine sampling programs is compared to a real-time monitoring program. The results are illustrated by tradeoff curves that demonstrate the benefits provided by a sensor network given an intentional biological or chemical attack. Further, the results show that response time is critical and physical sampling-based monitoring with sample collection frequencies of 24 h or longer are much less effective than real-time monitoring.