Annual Distribution System Flushing Program

The Prince William County Service Authority is conducting its annual water distribution system flushing program. Each spring, the Service Authority’s drinking water providers, Fairfax Water and the City of Manassas, temporarily change the primary disinfectant in their water treatment process from chloramines to free chlorine. Our water providers indicate that this temporary change facilitates an effective flushing program for the distribution system and is a drinking water industry best practice.

As part of the program, the Service Authority will be flushing its water mains between late March and mid-May by opening fire hydrants and allowing them to flow freely for a short period of time. Customers might notice the following throughout system flushing:

• Service Authority personnel and trucks performing system flushing activities in their neighborhoods.
• A slight chlorine smell in their tap water. We suggest that customers fill a pitcher with water and leave it uncovered on the counter, which will allow the odor to dissipate within a couple of hours.
• Brief periods of cloudiness in their tap water. The Service Authority recommends running the cold-water tap for approximately two minutes to reduce cloudiness.

To view frequently asked questions about the system flushing program, please click here.

The Service Authority will also provide timely updates about its system flushing program on Facebook and X. These updates will specify the areas of the County where crews will be flushing water through hydrants during specific date ranges.

Projected Pressure Zone System Flushing Dates

Current System Flushing Locations