AWWA ACE69098

This powerpoint presentation begins by presenting AwwaRF Project # 3022 - Cross Connection and Backflow Vulnerability: Monitoring and Detection, and then provides project objectives that include the following: develop occurrence data for residential backflow; develop a multiple sensor platform (pressure transient monitors, water quality monitors, backflow sensing meters) to evaluate how to detect residential backflow occurrence; and, develop protocols for responding to backflow incidents. Background information is provided on residential meters and online water quality monitors. A pilot test plan is presented and includes the following: constructed 200' pipeloop (4" diameter) with pumps and controls; installed 5 water quality monitors (sidestream panels, sidestream probe, and in-pipe sonde) with data collection; TOC, chlorine, conductivity, pH, ORP, UV-Vis absorbance, turbidity, pressure, temperature; ran baseline tests (continuous flow) to determine fouling frequency and maintenance requirements for 5 months; and, ran spiking tests to determine sensitivity of monitors to small changes for a number of 14 surrogates. Pilot test results indicated a lime spike and included the following: spiked solutions of varying lime concentrations (1-10 mg/L) and 1 mg/L Fe2+ in chlorine-free water in order to simulate groundwater intrusion through a leaking pipe; and, measured responses of pH, ORP, chlorine residual, turbidity, and conductivity. Growth media spiking is presented, along with a field test plan. Preliminary conclusions indicate that: water meters are capable of measuring small amounts of residential backflow - the public health significance of these are unclear; backflow signals from water meters may signify serious issues - utilities should have protocols in place to identify and investigate these occurrences; water quality monitors are sensitive enough to measure small (<5%) changes in water quality for many parameters; a wide range of monitors are available for different utility needs - O&M expenditures may not be very large; and, real-time data handling and analysis major impediment as huge amounts of data can be collected. Includes table, figures.