The Threat Ensemble Vulnerability Assessment (TEVA) Program for Drinking Water Distribution System Security

The increased risk of terrorism to our nation's critical infrastructure has focused national attention on the vulnerability of drinking water systems to the intentional introduction of chemical, biological, or radiological contaminants. EPA is developing the Threat Ensemble Vulnerability Assessment (TEVA) Program to analyze the vulnerabilities of drinking water distribution systems, measure public health and economic impacts, and design and evaluate threat mitigation and response strategies. TEVA is a probabilistic framework for assessing the vulnerability of a water utility to a large range of contamination attacks. Monte Carlo simulations generate ensembles of scenarios, and statistics are analyzed to explore the feasibility of scenarios, identify vulnerable areas of the water distribution network, and analyze the sensitivity of the model to various parameters. Preliminary results are available that illustrate applications of TEVA to three drinking water distribution systems of different sizes.