AWWA WQTC71410

This powerpoint presentation begins by providing a brief overview of distribution system (DS) contamination through intrusion. The primary study objective was to estimate the public health risk associated withnegative pressure events in a full-scale DS. Specific study objectives included: developing a transient model for evaluatingpressures during downsurge events based onfield measurements; estimating potential intrusion volumesconsidering two pathways, leakage orifices and submerged air vacuum valves (AVV); and, approximating concentration of contaminants atconsumption nodes. Transient analysiswith commercial software is presented, along with the impact of reduced wave speedon simulated pressure profiles, the impact of reduced wave speed on the extent of negative pressure zone, estimation of intrusion volumes, and estimation of theoretical intrusion volumesthrough leakage orifices using recordedpressures. Detailed conclusions are provided for wave speeds and for theoretical vs modeled intrusion volumes. Includes figures.



Keywords: Pressure; Modeling; Leak Detection; Water Contamination; Distribution Systems; Software