Impact of variable speed pumps on water quality in distribution systems

Abstract

Water quality has become a prominent issue in the study of water distribution networks. Variable speed pumps (VSPs) can control and improve the performance of water distribution systems. However, they may have eects on the water quality. e objective of this study was to investigate the impact of VSPs on water quality. e EPANET water quality simulator was applied for modelling water age and chlorine residual in a distribution network. In addition, intrusion of an active contaminant and analysis of leakage eects on residual chlorine concentration were performed through extended period simulations. Results indicate that VSPs may have negative impacts on water quality, including increased water age during low consumption times, and reduced disinfectant residuals at peak hours. In addition, the average rate of chlorine decay for xed speed pumps (57%) is higher than that for VSPs (54%) when a conservative contaminant (sewage water) is considered.

Keywords: Water distribution systems, pumps, variable frequency drives, water quality, extended period simulation