Water Security Initiative: Innovative Tools for Response Sampling Using Hydraulic Models

摘要

Many utilities maintain hydraulic and water quality models for operational and planningrnpurposes; however continuous, real-time modeling of a system to inform response actionsrnduring a crisis is not viable, especially for large, complex networks. To date, there has beenrnno guidance developed to help determine where best to collect samples in response to arnsystem-wide contamination threat. In response, the U.S. Environmental Protection Agencyrnand the Greater Cincinnati Water Works collaborated to develop a Contaminant TransportrnField Guide which can assist utility emergency response personnel in creating a samplingrnplan during the initial stages of such a threat. This work is based on a simplifiedrnrepresentation of a distribution system that was evaluated using the utility's existingrnhydraulic model to predict contamination transport. This was accomplished by dividing therndistribution system into defined pressure, or "pito" zones, tracking the spread ofrncontamination from zone to zone under different demand conditions over several timernintervals, and then presenting the impacts in the form of a matrix. Further, each zone wasrnthen investigated to identify sampling locations that were representative of the water enteringrnand, where applicable, leaving that zone. The evaluation and presentation of the model inrnthis fashion has several notable impacts for consequence management. This paper details therndevelopment, uses and benefits of this innovative Field Guide, and the model-based matrix itrnis built from.