AWWA DSS63740

This slide presentation outlines operation and modeling approaches for addressing water quality problems in the distribution system used by the Greater Cincinnati Water Works (GCWW) when it underwent a distribution system expansion. Water quality concerns included: infrastructure sized for future demand; initial demand minimal; and, sampling stations installed to monitor water quality. Solution approaches included both operational and re-engineering. Operational approaches included change tank operation and implement weekly flushing program. The re-engineering approach included division valve installation, and main extension and tie-in. Modeling results are provided on water age. Conclusions included: re-engineering activities can provide long-term solutions to water quality problems in the distribution system by minimizing retention time; water quality sampling, operation approaches, hydraulic modeling and water quality modeling are useful tools in addressing retention time issues; and, re-engineering activities can have positive impacts in one area and negative impacts in another. Consider the impact of re-engineering activities on the entire distribution system. Includes table, figures.