Susceptibility of Distribution Systems to Negative Pressure Transients

Book excerpt: Low or negative pressure transients (also called surge or water hammer) create temporary opportunities for external chemical and microbial contaminants at higher pressure to enter the water distribution system, creating potential health hazard and potential weakening of distribution pipes, leading to failure. This study investigates how such events as power outages, pump shutdowns, valve operations, main flushing, firefighting, and main breaks can create significant rapid, temporary drops in system pressure. The report offers useful recommendations for using surge models to optimally locate pressure monitors and to minimize the occurrence and impact from low- and negative-pressure transients.