Fairfax Water is opening hydrants to flush water mains

Fairfax Water will be flushing its water mains by opening fire hydrants and allowing them to flow freely for a short period of time, starting May 21.

This is done every spring to maintain the high quality of water in the system, Fairfax Water says. The work should be finished in May or June.

At the same time, Fairfax Water’s treatment process will switch from combined chlorine to free chlorine in order to facilitate the flushing.

“Flushing may result in temporary discoloration and the presence of sediment in your water,” Fairfax Water says. “These conditions are not harmful and should be of very short duration.”

Throughout the year, chloramines, also known as combined chlorine, are added to the water as the primary disinfectant. During the spring flushing operation, chlorine is added in an uncombined state, commonly referred to as free chlorine.

Free chlorine is quicker acting than combined, which allows it to react with sediments suspended during flushing.

Depending on one’s usage patterns and location within the distribution system, it could take up to a week for the drinking water to transition from combined to free chlorine at the beginning of the flushing program or from free to combined chlorine when it ends.

Some customers might notice a chlorine taste and odor in their drinking water while free chlorine is used. If that’s a problem, Fairfax Water recommends keeping an open container of drinking water in the refrigerator. This will enable the chlorine to dissipate, thus reducing the chlorine taste.

Anyone with an aquarium or pond should always test the water to be sure it’s free of chlorine before adding fish or other animals.

The flushing operation will be carried out in neighborhoods by Fairfax Water employees. They will be easily identifiable – driving vehicles and wearing uniforms with the Fairfax Water logo.

For more information contact the Fairfax Water dispatch operator 24/7 at 703-698-5613.