West End Hydrant Flushing

During the week of September 14th, Public Works will be flushing all the water hydrants located west of 1st Avenue.  This flushing process removes naturally occurring minerals and sediment that build up in water mains over the course of the year and allows Public Works to collect key data about the system.  During flushing, they check water pressure to confirm the system is operating correctly. Just as importantly, by opening each fire hydrant in the water distribution system, we ensure each one is properly maintained and available for use in the event of a fire.


When you see water running down the street as crews work on fire hydrants, it may appear to waste water.  Actually, this important preventative maintenance activity maintains the integrity of the water system and allows us to continue to deliver the highest quality water possible to our customers.


As a result of the line flushing process, residents in the immediate vicinity of the work may experience temporary discoloration of their water.


This discoloration consists primarily of harmless silt and air and does not affect the safety or quality of the water. If you experience discoloration in your water after crews have been flushing in your neighborhood, run the cold water faucet in your basement for a few minutes to clear the pipes.




Q: Why does the water system need to be routinely flushed?


Without regular flushing, sediment materials may cause water quality deterioration, taste and odor problems, or discoloration of the water. Water may also stagnate in lesser used parts of the distribution system. This can result in degraded water quality.


Q. What should I do when I see Public Works crews flushing hydrants in my area?


If you see Public Works flushing hydrants, please drive carefully and watch for workers in or near the roadway. In addition, the roads will be wet and the water may pond in low-lying areas for a short period of time. Inside your home, avoid turning on any faucets or fixtures while crews are flushing the hydrants. This may draw discolored water into your home piping. In particular, avoid washing clothes during the flushing operation. Discolored water may be drawn into the washer and potentially stain clothing.


Q. How will this affect my water?


During the flushing process, water customers may experience some disturbance in their usual water service such as a short-term decrease in water pressure or discolored water. Although the water does not pose a health risk, it is recommended to avoid drinking the water until it runs clear from the tap.


  • Don’t prepare baby food or formula if the water is discolored. Use bottled water or pre-prepared food and formula. You can also boil the water for 5 minutes to ensure safety.

  • Do not wash clothes if the water is discolored.

  • It is okay to use the water for showering, bathing, and toilet flushing.


Q. What should I do after the flushing?


If you use tap water during or immediately after flushing, it could come out with sediment or be discolored. If it’s discolored, shut the water off and wait approximately ten minutes. After ten minutes, open several cold water faucets in your home allowing new water to work its way into your pipes. Leave the faucets running for several minutes until the discoloration is gone and the water runs clear. In some infrequent cases, customers may experience slight discoloration for a few hours. This discoloration only affects the appearance of the water; it does not affect the taste or water quality. Lastly, avoid washing laundry until the water is clear from the tap. Wash a load of dark clothes first.


Q. How long does it take to flush a hydrant?


Hydrant flushing takes about 15 minutes.


Q. What should I do if my water pressure or volume seems low after flushing?


Check your faucet and washer screens for trapped debris.


Q. Why does the water look funny after hydrant flushing?


When a hydrant is opened, there will always be temporary incidences of discolored water containing fine sediment particles making the water appear brown or rust-colored. Fine air bubbles may also mix in with the water giving it a milky appearance. While discolored water does not pose a health risk, you should allow a few hours for discoloration to dissipate. To verify the water has settled, let your cold water tap to run a few minutes. If the discoloration persists for more six (6) hours, please contact Public Works at (708) 447-4211.


Q. Is it OK to drink sediment-laden or discolored water during temporary disturbance events?


We recommend water users wait until the water has cleared before using it for potable purposes (cooking/drinking) or for washing clothes.


Q. What is the sediment in the water system and how does it get there?


Water naturally contains minerals which react with the inside of the pipe to produce the sediment by-product. This chemical reaction between the pipe and water is a normal and natural process. Sediment can also build up inside of the pipe and prevent an adequate volume of water flow. The flushing process removes much of this by-product.


Q. What takes place during hydrant flushing?


System valves are opened and closed during the operation to control the direction of the water flow. Because North Riverside’s water mains are designed to handle fire flow (which is much greater than domestic or commercial water flow), the velocity of flow in most mains is fairly low. Due to this, 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 or stale water.


During flushing, Public Works opens each hydrant to its maximum flow. This high flow stirs up iron deposits and other settled materials and pushes them out of the system. The operator also records the pressure and flow of water at each hydrant, as well as cleaning and lubricating accessible operating parts. Any issues with the hydrant are noted and it is placed on a schedule for repair. The flow and pressure data is shared with the local fire department.


Q. Doesn’t the hydrant flushing program waste water?


While it may appear 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 so it can be accounted for and tracked along with other uses of water.