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Injection of Contaminants into a Simulated Water Distribution System Equipped with Continuous Multi-Parameter Water Monitors
Citation:
RYAN, J., R. Mangaraj, JEFF Q. ADAMS, AND E. N. KOGLIN. Injection of Contaminants into a Simulated Water Distribution System Equipped with Continuous Multi-Parameter Water Monitors. Presented at AWWA WATER SECURITY CONGRESS, CINCINNATI, OH, April 06 - 08, 2008.
Impact/Purpose:
to present information
Description:
The U.S. EPA’s Technology Testing and Evaluation Program has been charged by EPA to evaluate the performance of commercially available water security-related technologies. Multi-parameter water monitors for distributions systems have been evaluated as such a water security technology throughout 2007. Five different water monitors were verified in this evaluation which was conducted using EPA’s newly constructed recirculating portable pipe loop. The portable pipe loop has a footprint of approximately 7’× 14’ and can provide flows of 10 to 161 gallons per minute at a wide range of pressures. The water monitors included sensors for: free chlorine, monochloramine, pH, conductivity, dissolved oxygen, oxidation reduction potential (ORP), turbidity, and chloride. Total organic carbon (TOC) was also monitored in order to observe its response to various contaminants. The experimental plan included two major components. First, the accuracy of the measurements made by the water monitors was evaluated during periods of stable water quality conditions by comparing each sensor measurement to a grab sample result generated using a standard laboratory reference method and then calculating the percent difference. The second stage of the verification test involved evaluating the response (both response time and magnitude of response) of the water monitors to changes in water quality parameters caused by injecting 20 different contaminants including (among others) potassium cyanide, cesium chloride, strychnine, Bacillus anthracis, Yersinia pestis, Franciscella tularensis, sarin, soman, and VX into the portable pipe loop. Injections of the contaminants were made in at least three different concentration levels ranging from 0.01 mg/L to 10 mg/L into the recirculating portable pipe loop containing finished drinking water. Overall, free chlorine, ORP, and TOC were the measurements that were most effected by the contaminant injections, depending on the contaminant that was injected. The concentration level at which each contaminant changed (if it did at all) each water quality parameter will be reported during this presentation.