Loudoun Water conducts controlled flushing of its watermains annually in the spring to ensure high standards of water quality and proper operation of valves and fire hydrants. Loudoun Water may also flush watermains as needed to address periodic issues with water quality. Flushing is an effective first step in clearing the lines when water quality appears degraded.

Watermains are flushed by opening fire hydrants and allowing them to flow freely for a short period of time. The flushing cleans out sediment and other particulates, which accumulate normally in the watermains. Loudoun Water also tests and performs routine maintenance on valves and fire hydrants during the flushing operation.

The water is safe to drink and use during flushing. However, flushing may result in some temporary discoloration or a milky appearance. It may also result in some sediment in the water. If discoloration or sediment is evident, customers may want to avoid doing laundry for that day. The milky appearance is just air bubbles that were introduced into the water during flushing.

Smelling Extra Chlorine?
You may notice a more pronounced chlorine taste or odor in the water during springtime flushing. This is because our largest supplier, Fairfax Water, switches from chloramines to free chlorine as a disinfectant during flushing to optimize treatment. Free chlorine has a more noticeable chlorine taste and odor than chloramines. This will dissipate when water is left in an open container in the refrigerator. Letting water in a glass sit for a moment will also take care of air bubbles that are stirred up during flushing and cause the milky appearance.

Loudoun Water is unable to advise customers of the exact date the watermains serving a particular area will be flushed or whether water service in an area will be affected. If your service is currently affected, it should only be for a short period, usually no more than a couple of days. We regret any inconvenience flushing may cause.