Water Main Flushing

About Water Main Flushing

Team of Employees Standing in Front of Company TruckWater main flushing is a necessary program for water agencies to keep up their infrastructure and ensure high-quality water. The traditional procedure includes opening up fire hydrants to scour and remove the buildup in pipes that may cause discolored water. As water flows at high velocities through the mains, encrustations, biofilm and fine sediment are dislodged. The resulting discolored water leaves the distribution system through the open fire hydrants, runs down the street and out to the sewer or storm drain systems. In May 2016, the District re-initiated its Flushing Program which was suspended due to the water shortage condition in the Mid-County region, and began using a machine called the NO-DES which all but eliminates water waste during the flushing program. The NO-DES machine, however, is not able to flush all areas of the distribution system, so traditional flushing may be performed in these areas.

District customers may temporarily experience discolored water during water main flushing. Water users are advised not to be alarmed if water looks rusty as this discolored water is caused by sediments being stirred up within the water mains. If you experience any of these changes or if you see some cloudiness or rust color in your water, we recommend you flush the pipes of your home. Flushing of your home's pipes is accomplished by opening your front outside hose bib until it runs clear. If the water does not clear the first time, wait a few minutes and run the water again. It is also advised that you make sure your water is clear before doing laundry or other projects for which discolored water could cause problems. It is important to not run hot water if you notice it is discolored, as the discolored water can be drawn into the hot water tank.

Innovation Technology Recaptures Water from Main Flushing

NO-DES DiagramBy linking together two fire hydrants via a pump, oversized fire hose and filtering system mounted atop a flatbed truck, the NO-DES system circulates water at optimum velocities in a temporary loop. The water passes through filters which removes the sediment and particulates and is returned to the district's water pipes. Disinfectant can be added to further improve water quality. Inline turbidity meters indicate when desired clarity levels are met. No water is flushed into the street! The majority of the NO-DES truck purchase was funded by the District's Water Demand Offset program.