Contaminant Intrusion in Water Distribution Systems; An Ingress Model

摘要

In a water distribution system, a lowegative pressure event occurs under daily operation that may lead to contaminant intrusion. To assess the risk associated with contaminant intrusion, exposure assessment is required. To have more accurate intrusion exposure assessment, the impacts of surrounding soil on intrusion rate must be considered. This research proposed a model to make a more realistic estimate of intrusion rate. To screen the effect contributing factors, a two-level factorial design was used. The Bukingham π-theorem was applied to group the influential factors into a set of dimensionless π-parameters. The relationship among the π-parameters was obtained by using the numerical data generated by a two-dimensional finite element model for flow in a saturated zone surrounding a pipe. A regression analysis was then applied to find the best fit to the results.