Flushing hydrants is an important component of a routine maintenance program necessary to maintain the integrity of the water system. This allows the City to continue to deliver high quality water to our customers. It is necessary to periodically flush water through the main lines in order to protect the quality of your drinking water. The volume of water that is released through a fire hydrant quickly flushes off sediment that accumulates on the bottom of the water mains and helps keep the water in the system fresh and clean. This is an important preventative maintenance activity.
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Regular flushing improves drinking water quality by removing sediments from inside the mainline and flushing them out through the hydrant. It also serves to identify malfunctions of the hydrant and related valves.
The City utility maintenance crews typically flush hydrants throughout the city one time in the spring and again in the fall. Hydrant flushing occurs during construction and water main breaks as well.
You may notice a color change in your tap water following the flushing of the water main, during construction near your street and following a nearby water main break. The discoloration is normal and will last only a short time after the nearby hydrants have been flushed. When a hydrant is opened, the water in the mainline flows out at a high velocity. This creates a scouring action in the pipe which dislodges fine sediment particles that have accumulated in the pipe. The discoloration is due to suspended particles mixing with water that do not immediately settle.
During construction, frequent opening and closing of the gate valves leads to the same scouring action as during flushing. A significant amount of hydrant flushing occurs during construction and water main breaks, but some sediment usually ends up in water services too. There are no known health hazards associated with the discolored water.
The discolored water is safe for drinking, but you may choose to reschedule laundry, especially whites, or other work that may be impacted by discoloration. The best way to clear the water is by turning on the cold water in a basement utility tub or an outside spigot for a few minutes. If that doesn’t clear it up, please contact City Hall at 651-204-6000. The hydrants may require additional flushing.
Once in a great while, your water may have a “rotten egg” odor. This odor is caused by hydrogen sulfide gas. The odor is unpleasant, but the gas is not usually harmful at the low concentrations that occur in household water systems. For advice on how to get rid of the odor, please contact our City Engineer at 651-204-6050.