Water Main Flushing
In the warmer months of the year (generally April-November), the PWSB runs the water main flushing program. The purpose of water main flushing via hydrants is to improve water quality throughout the system by removing mineral and sediment buildup from water mains. Another added benefit is the ability to verify proper operation of all hydrants in the system and evaluate the available flow to each hydrant.
In 2021 a new method of water main flushing was implemented, called unidirectional flushing (known as UDF). With UDF, each pipeline is isolated to create flow in a single direction and quickly clean the pipe. By concentrating the flow, UDF creates higher velocities to clear the pipes and requires less water.
Please follow this link to view an informative infographic about the benefits of unidirectional flushing
Nighttime unidirectional flushing by the PWSB was halted for the season on October 28, 2021. All of Central Falls and Cumberland have been completed and approximately a third of Pawtucket was completed.
Overall, the project was deemed successful as less water is utilized, and this method scours the inside pipe wall to remove “biofilm”. The program will recommence in early spring 2022 in order to complete the remainder of the system.
The unidirectional method will likely be the preferred option for flushing the distribution system in moving forward.