“Remote Monitoring and Network Modeling: Their Potential for Protecting the Nation’s Water Supplies” by Robert M. Clark, Senior Research Engineering Advisor, National Risk Management Research Laboratory, USEPA, Cincinnati, OH 45268, Roy Haught, Water Supply and Water Resources Division, National Risk Management Research Laboratory, USEPA, Cincinnati Ohio 45268 and Srinivas Panguluri, Project Engineer, Shaw Environmental, Inc., Cincinnati Ohio 45268.
ABSTRACT: In October of 2001, as a result of the events of September 11, the Administrator of the U.S. Environmental Protection Agency (USEPA) created the Water Protection Task Force (WPTF). The WPTF was given the responsibility for developing strategies and guidance for protecting the Nation’s 54,000 community water supplies. These systems serve nearly 264 million people. Eighty percent of the US population is served by 14 percent of the utilities. The remainders of these utilities ( 86 percent) serve relatively small populations.
One of the WPTF’s first assignments was to develop a State-of-the-Knowledge report for the newly created Office of Home Land Security. The report, which is currently in review status, summarizes current knowledge and information on the characterization, identification and control of biological and chemical threat agents. It will be used to establish priorities for water security related research in the US. In the report water distribution networks have been identified as a major area of vulnerability. Of particular concern is the need to predict the movement of contaminants in distribution systems and to monitor their concentrations at various points in the network. However, tracking contaminant movement and contaminant concentration in a network is extremely complex and will require a combination of mathematical models and real time monitoring. EPA has developed a public sector model called EPANET that can predict the propagation of contaminants in networks. Commercial spin off from EPANET are now available that can provide even more sophisticated predications then EPANET.
However, the linkage of network n models and real time monitoring is still an activity for research and development. EPA is currently conducting research into the development of sensors and monitoring systems that have the potential for measuring contaminants in distribution systems. Initial research focused on standard sensors for remote measurement of turbidity, chlorine, nitrate and fluoride for controlling small water treatment plants. Subsequent research has focused on measuring chlorine residuals, pH and temperature in distribution systems. Initial testing was completed in a pilot network located in EPA’s Test and Evaluation Facility in Cincinnati Ohio. The monitoring system was field tested in Washington, D.C. where it was used to monitor chlorine residuals in three locations in the Washington, D.C. water system. Currently the development of more sophisticated monitors is underway. For example, EPA is exploring the use of a finger print analysis technique that might be able to identify the intrusion of a wide range of contaminants into a distribution system. It is anticipated that the combination of real time monitoring and water quality modeling will provide a very effective tool for enhancing water system security.