You might be asking what it is they are doing when the staff is flushing the distribution system. The short answer to that question is that we are removing sediment and minerals that have collected in the distribution system during the slowest time of usage. Most water distribution systems are sized primarily to meet Fire Flow, which means the volume and velocity of the water moving thru the pipe during normal domestic usage is very low. This low velocity allows for sediment and minerals to precipitate and settle in the mains. This sediment can cause color issues and even taste and odor issues if not routinely removed.
When we are flushing, we purposely open hydrants in strategically predetermined locations in order to simulate the hi-velocity water flows a fire situation would generate. The benefit of generating these high velocity flows, and in some cases flows in the opposite direction as domestic usage, is that they scour the main and remove unwanted sediment and minerals that have collected over the winter. We run the water out of the hydrants until all noticeable discoloration is gone; then we run the water for a bit longer to make sure the water is clear.
After the flushing of that portion of main is complete, we shut down the system and return it to its domestic role. Then we move on to the next portion of the main, moving progressively away from our tank sites so as to keep moving any potentially discolored water away from the new water being put into our distribution system.
What will you see while we are flushing? You will likely notice our truck parked alongside of the roadway with a District employee connecting a hose to a hydrant. On the end of the hose is a device that diffuses the water flow to reduce any damage, and one employee will be following the water to make sure it is draining in a safe manner and is not generating any unforeseen issues.
What can you do to help? All you need to do is look for signs in your area indicating when flushing will occur, read the notices provided, and if you do have some discoloration during this process, please run the tap for 5-10 minutes. If this doesn’t clear up the water, then let us know. The other important thing you can do to help is to slow down when you see the flushing crew, as there may be water on the roadways for short periods during these operations. Please watch for our employees, and drive slowly through any standing water you may encounter.
This process will be occurring throughout the District between March through May, so look for the signs, drive carefully, and enjoy the quality, clean, safe drinking water that it is our great privilege to provide to you. Thank you for visiting our website. If you have any questions, please don’t hesitate to ask our qualified, courteous customer service representatives.