March 22, 2024

Loudoun Water and other utilities around the country begin hydrant flushing every spring as a way to clean their water distribution systems. Flushing in the Loudoun Water service area will begin the week of March 25th and will continue for about 12 to 15 weeks. 

The flushing of hydrants around the service area will have no effect on water usage. For the safety of our employees and community residents, we ask that you do not approach them while they are working.

At each stop, a staff member will open a hydrant and take samples to measure water quality. Hydrant flushing has several benefits including clearing sediment from the lines, giving crews a chance to monitor our system and ensuring high standards of water quality. 


A flushing map is available to see where our crews will be flushing each week.
You will be able to recognize our employees by a number of identifiers:

  • Loudoun Water employees will be driving vehicles with the Loudoun Water logo
  • Loudoun Water employees will be wearing uniforms with the Loudoun Water logo

If you have any questions or concerns about flushing or the crews in your area, please contact our Customer Relations department at 571-291-7880 and they will be happy to assist you.

Frequently Asked Questions:

What’s that taste?
During Spring flushing, some customers may notice a more pronounced chlorine taste or odor in the water. Fairfax Water (our wholesale water provider) temporarily switches from chloramines to free chlorine during each spring. Loudoun Water also switches from chloramines to free chlorine during each spring.  Free chlorine serves as an aggressive disinfectant that aids in the disinfection of the flushed water mains. Filling a pitcher with water and placing it in the refrigerator will help to alleviate the chlorine taste. After springtime flushing is complete, Fairfax Water and Loudoun Water will switch the disinfectant back to chloramines. This is standard practice for many water utility systems throughout the United States.

Why does water have a 'milky' or 'bubbly' appearance during flushing?

This is simply a result of the oxygen in the water being stirred up during flushing causing visible air bubbles. Letting the water sit in a glass for a few seconds will take care of the air bubbles! With this phenomenon, you will see the bubbles clear from bottom to top.

Why is my water discolored?

Flushing may result in temporary discoloration and the presence of sediment in your water. These conditions are not harmful and should be of very short duration. If noticed, avoid doing laundry during this time (while crews are on your street) to avoid discoloration. If water remains discolored or cloudy for an extended timeframe contact Loudoun Water Customer Relations at 571-291-7880.

Will my water pressure be affected?

Some customers may notice a slight pressure fluctuation when our crews are working on their street. Pressures will return to normal once the flushing has finished.

Are my fish safe during the disinfectant switch?

You will need to treat tap water before using it in a fish aquarium. Disinfectants can harm fish. Check with a local pet store to learn what types of chemicals you need to add to the tank to neutralize the effects of the disinfectant.

Why isn't the water captured or reused?

There are a lot of variables that make the process of capturing, collecting and transporting the water difficult. The amount of pressure released when hydrants are flushed makes it very difficult to recapture.

Who pays for this water?

The cost of hydrant flushing is built into the normal cost of operations.