Consequence Management Optimization for Contaminant Detection and Isolation

Abstract

Vulnerability assessments may be used to help identify components of water distribution systems that require strengthening against possible attacks, including physical destruction and/or chemical contamination. Numerous recent research efforts have focused on the placement of sensor systems to aid vulnerability assessments associated with contamination events. A related issue is the probability of isolating a contaminant following sensor detection. In this current effort, we utilize three optimization techniques: (1) an unconstrained first-order reliability method (FORM); (2) a constrained FORM; and (3) parameter estimation (PEST), to determine the optimal demand to reduce contaminant concentration. This aids in consequence management of contamination events by supplying water distribution system operators with additional information to remediate contaminated sections. Application of these techniques to a relatively simple network and a moderately complex network demonstrates the usefulness of optimization methods in determining optimal demands in order to reduce contaminant concentration. Although each of the techniques performed well for this example, PEST illustrated greater capabilities in determining the most optimal solution.