EPA has released Distribution System Water Quality Monitoring: Sensor Technology Evaluation Methodology and Results – A Guide for Sensor Manufacturers and Water Utilities, which summarizes the results of tests with various online (i.e., real-time) water quality sensors to see if they could provide dual use for early warning of intentional contamination, as well as monitoring general water
quality. Only sensors most commonly used by water utilities were tested.
Free chlorine and total organic carbon (TOC) sensors were the most successful in detecting a number of chemical and biological contaminants.
- Free chlorine levels noticeably dropped in the presence of various contaminants
- TOC sensors were successful in detecting carbon containing contaminants or carrier liquids
EPA- Distribution System Water Quality Monitoring: Sensor Technology Evaluation Methodology and Results
This report, titled “Distribution System Water Quality Monitoring: Sensor Technology Evaluation Methodology and Results – A Guide for Sensor Manufacturers and Water Utilities,” provides an overview of the U.S. Environmental Protection Agency’s (EPA’s) research results from investigating water quality monitoring sensor technologies that might be used to serve as a real-time contamination warning system (CWS) when a contaminant is introduced into a drinking water distribution system. EPA’s concept of CWS for protecting water distribution systems is discussed in Chapter 1.0. A principal component of such a system is online water quality monitoring.
Based on a review of available online water quality monitoring sensor technologies, an early determination was made that it was not technically feasible to accurately identify and quantify the many different types of contaminants that could potentially be introduced into the drinking water supply/distribution system. Furthermore, because online sensor technologies need to be economically suitable for mass deployment within a distribution system, EPA focused its research on identifying sensor technologies that could be used to detect anomalous changes in water quality due to contamination event(s). Once a water quality anomaly is detected, the water utility operator is alerted, and further actions (e.g., sampling and analysis) could be undertaken by the operator to identify and quantify the contaminant if necessary. This report focuses on EPA’s research on pilot-scale evaluations of available online water quality monitoring sensor instrumentation.