Uni-directional Water Main Flushing

Uni-directional Water Main Flushing

What is it?  Uni-directional flushing is a routine process of cleaning the piping of the water distribution system.  Most water providers conduct a systematic and controlled flushing program to remove sediments and stale water and to help maintain chlorine residuals throughout the system.  Flushing improves the overall quality of the water in the distribution system and assists in the overall system maintenance.

Why is the Village doing it?  The water mains are designed to handle fire flow, which may be several times larger than domestic or commercial water flow.  The velocity of flow (or rate that water flows through pipes) in most mains is normally fairly low.  Due to this, mineral solids may settle on the bottom of the pipes.  The problem may be more significant where there are dead-end pipes or areas of low water use.  Over time, these deposits reduce the “carrying capacity” of the pipe.  They can also be a source of color, odor and taste problems in the water if the deposits are stirred up by increases in the flow.  Flushing the pipes at high velocities will normally remove most of the settled substances and discolored water.

Doesn’t this flushing program waste water?  While it may appear to be wasteful, flushing is the most effective way to keep our drinking water safe, clean and pleasant tasting.  Crews conducting the flushing keep careful records of the amount of water that is flushed through the lines.  Therefore, this water is accounted for and tracked along with other uses of water.  This is a preventative maintenance program, so a little planned flushing now can save a lot of unplanned flushing later.

How exactly is the process carried out?  Crews will arrive on the scene and locate the specific hydrant, making sure that appropriate valves are either open or closed according to the need.  They will also attach a diffuser to the outlet of the hydrant.  The diffuser will spread the water over a larger area, so that sidewalks, roads and unpaved surfaces are not damaged.  Crews will then fully open the hydrant and keep the water flowing at this high velocity until the water is clear.

Why can’t you tell me exactly what days my streets will be flushed?  The Village tries to maintain a schedule of flushing, but due to possible emergencies or inoperable valves there could be changes in the schedule.

What else do Village water customers need to know to prepare for the flushing process?  During the actual flushing process, water customers may experience some disturbance in their usual water service such as a short-term decrease in water pressure or the appearance of “brown water”.  Although the water should not pose a health risk, it is best to avoid drinking the water until it runs clear from the tap.

Avoid washing clothes during the flushing times.  Plan ahead and do your laundry over the weekend to avoid the possibility of having stained clothes.  If you inadvertently have washed your clothes in “brown or discolored water”, DO NOT USE BLEACH.   The Water Department recommends using “Iron Out” laundry detergent.  Do not prepare baby food or formula if the water is discolored.  Use bottled water or pre-prepare food and formula.  You can also boil the water for 5 minutes to ensure safety.  It is okay to use the water for showering, bathing and toilet flushing.  It’s often a good idea to use water stored in the refrigerator to drink, even when the flushing program is over.  This is a good habit to get into to save water running from the tap until it gets cold.