High Maintenance Hydrants:
How does distribution system flushing by utilities impact treated water quality that customers experience?
Results from a civic campus collaboration to raise the bar for flushing programs, which are common low-barrier opportunities to monitor and improve water quality after treatment
Drinking water utilities routinely flush water from the distribution system to maintain integrity of the infrastructure and improve water quality for customers. Almost all utilities around the world conduct some form of flushing in their distribution system at least once per year. Flushing programs are one of the few ways water providers can easily and non-invasively monitor and manage the health of distribution pipes and integrity of distributed water quality. More than that, in an industry largely hidden from the public eye, flushing activities place water professionals in the physical spaces where the people they serve can see them and the work they do to ensure safe drinking water.
On the surface, flushing water from the system may seem like a fairly simple operation. However, as you will see in this module flushing induces complex interactions between hydraulic flow, the distribution system environment, and water quality. It can be a powerful tool for distribution system and water quality management, but also can be difficult to control and achieve desired results.
This module provides a foundation of how distribution system flushing works to impact water quality. A case study from collaborative research with the City of Ann Arbor provides a jumping off point to learn about what is going on down in the pipes to cause changes in water quality. By the end of the module, you will reflect on the mixed results observed in Ann Arbor's program to think about what may have been the cause and what solutions may help optimize their program.