Pilot water flushing program to help with long-term water efficiency

During the month of May and June 2013, Environmental Utilities, Water Division will be flushing select hydrants in two small areas of the City. The first area is scheduled for May 14-16 in the neighborhood bounded by Foothills Blvd., Country Club, Mcanally and Junction. The second area is still being developed.

Crews will place sandwich boards in the neighborhood in advance of the work to alert customers. We will get the information posted on the City web site.

While this process may invoke images of “wasting water” in a dry climate year, here are some reassurances of why the flushing is needed:

• This is a pilot flushing program planned for only a few days at each location. The Environmental Utilities has suspended wide-spread system flushing in anticipation of a second dry climate year in 2014.
• The Unidirectional Flushing (UDF) pilot program will ultimately establish a protocol that will allow the Environmental Utilities to control and minimize the amount of water needed to effectively flush the water distribution system on an ongoing basis. This will increase our long term water efficiency and help with our 20 percent conservation by 2020 goal.

UDF Background

The City of Roseville has over 500 miles of piping used to convey potable water to homes, businesses and fire hydrants. The water entering distribution mains is of very high quality; however, water quality can deteriorate in the mains if the system is not well-managed. Proper management of this system requires that the Environmental Utilities routinely flush the distribution piping. Water main flushing is the process of cleaning or scouring the interior of water distribution pipes by sending a rapid flow of water through the mains and out hydrants. This process removes any built up sediment, freshening the water delivered to customers and helps insure that hydrants and valves in good working order. With the exception of drought stage years, Environmental Utilities has historically flushed sections of water mains annually.

Unidirectional Flushing (UDF) is a more systematic and deliberate approach using the water system computer model to develop a flushing program that uses less water and provides a more thorough cleaning of the distribution system. The water model predicts how much water will be used, the velocities within the pipes and the optimal valves to operate. The goal of this UDF pilot program is to have the consultant examine our current flushing procedures, employ our computerized water model to optimize the flushing operation on two small test zones and then analyze scaling up what is learned in the pilot tests to a City-wide UDF program. In addition, in going through this pilot study Environmental Utilities staff will gain an understanding of using this tool and will be trained to expand the program citywide if successful.

For specific questions on the program, please contact Environmental Utilities at (916) 774-5750.