It's Hydrant-Flushing Time, Says DPW
Apr 29, 2014 02:42PM ● Published by Pamela Johnson
Although hydrant flushing looks like wasting water, it is not. It is critical water system maintenance. Iron, manganese, and other minerals exist in low levels in the water we pump from all of our wells. These minerals settle out over time and cling to the water main pipe walls. Flushing the water mains and hydrants removes the accumulated mineral deposits and sediment. This helps to minimize unexpected dirty water incidents and improves water system performance.
High flushing flow rates are needed to loosen and remove these materials. The flushing process causes the water to become very discolored for a short period of time.
We try to flush out all discoloration; however, if a customer is using water at the same time we are flushing the section of main near their home, they may get some discolored water. If this occurs, it should clear up in an hour or less.
The flushing is being done using our uni-directional flushing program. The uni-directional flushing program utilizes computer generated models and system maps. There are three big advantages of uni-directional flushing: it minimizes the water needed to flush the system, it minimizes dirty water complaints during flushing, and it gives us insight into the condition of the pipes in our underground water distribution system.
The uni-directional flushing process requires that we shut down gate valves to isolate short sections of pipe. The program is set up to flush dirty pipes with water from pipes that have just been flushed clean. The sections of main being flushed are fairly small and flow in the pipes is in one direction. When a flushing hydrant is opened, water comes from recently flushed (clean) mains through un-flushed (dirty) mains and out the hydrant.
This process decreases the possibility of dirty water complains, but can affect water pressure while hydrants are flowing. Pressure drops should only last during the actual time that hydrants are open, which is typically less than twenty minutes.
Customers should not lose all water pressure. If they do, we have a valve closed that we think is open. If residents experience a complete loss of water pressure, they should contact the DPW at 508-966-5813 immediately.
The flushing will be done during the daytime hours, 7:00 am to 3:00 pm Monday thru Friday.
We recommend that customers check their water before doing any laundry. If rust stains appear on washed clothing, special iron removing detergent can be obtained free of charge from the Town Clerk’s Office and DPW Office. (Warning: do not try to bleach out stains. Bleach will set the stain and thereby ruin the fabric.)
Customers can call the DPW at 508-966-5813 for a daily update on the area of town where flushing will be performed. A posting of streets to be flushed is also updated regularly in this Town News section of our website.