Water Main Flushing Program
Water mains are flushed for several reasons. It allows hydrants to be periodically used and identified for maintenance or replacement and provides an opportunity for tests to be done to determine if water flow and pressure are sufficient.
Most importantly, flushing enhances water quality. It allows sediment built up in the water mains, especially dead ends and low-flow areas, to work its way out of the system. The high volume of water causes a scouring action that draws the sediment out. Left alone, this sediment may cause discoloration when water flow changes, ultimately making its way into customer's homes.
Iron and manganese, which are naturally present in Concord's groundwater, cause the sediment and color. It is recommended not to ingest (drink, cook, or prepare baby formula with) discolored water, but it is safe for activities such as bathing and dish washing.
Every neighborhood gets flushed roughly every other year. Additional flushing is conducted if sediment historically has built up in certain neighborhoods or if a large amount of customers in a certain area have had problems. A well-designed flushing program does not require water to flow from every hydrant. Our goal is to flush water mains, not hydrants.
Public notification of the flushing is key to minimizing disturbances in customers' homes. CPW publicizes the flushing schedule and general areas expected to be impacted one to two weeks before the flushing starts. Look for this information in the Concord Journal, Concord Cable TV (Channel 8), Social Media (Facebook and Twitter), email News and Notices News Flash and on this webpage.
It is important to remember that flushing can cause discoloration in other areas of Town not directly being flushed and street listings published only indicate the general areas being worked in.
Concord Public Works is mindful that the regional drought continues and after careful consideration evaluating broader water distribution system interests, at this time it has been determined that the benefit of unidirectional flushing activities are important to ensure that high quality water is maintained for essential uses like drinking water and for adequate fire protection. Water main flushing also allows for routine exercising of water main valves and hydrant inspection procedures.
Concord Public Works continues to monitor water supplies around the clock, if water main flushing needs to be postponed Concord Public Works may do so.