Our drinking water in Prince William County comes from four  different sources: (1) The Potomac River, (2) the Occoquan  Reservoir, (3) Lake Manassas, and (4) groundwater extracted by a  community well system. 

From Source to Tap, and Back Again!

Water begins its journey from the  Potomac River and is treated by    Fairfax Water at its James J. Corbalis,  Jr. Water Treatment Plant,  which is  then pumped to the western part of  our service area, including Haymarket,  Gainesville, and Manassas. These  areas are also supplemented by water  from Lake Manassas that is treated at  the City of Manassas’ Water Treatment   Plant. Additionally, our customers in the Bull Run Mountain and Evergreen areas are supplied with groundwater through community wells. 

After the treated potable water is used in the western part of our system, the wastewater is conveyed to the Upper Occoquan Service Authority’s wastewater treatment plant in Centreville, where it is cleaned and discharged to Bull Run, a tributary of the Occoquan Reservoir. The water in the Occoquan Reservoir is then withdrawn by Fairfax Water again and treated to potable standards at its Frederick P. Griffith, Jr. Water Treatment Plant in Lorton. After treatment, the potable water is pumped into the eastern part of our service area. The resulting wastewater is then conveyed to our H.L. Mooney Advanced Water Reclamation Facility, where it is treated to Chesapeake Bay clean water standards and discharged to Neabsco Creek, a tributary of the Potomac River.

Kayaker on the Occoquan River

Clean Water, Exceptional Infrastructure

Although the potable water we distribute to our customers is purchased wholesale from other suppliers, it is our responsibility to ensure that drinking water arriving at our customers’ homes and businesses, via about 1,300 miles of piping, meets or exceeds drinking water quality standards established by the Virginia Department of Health. We accomplish this by actively monitoring and aggressively testing the water throughout our distribution system.

Similarly, the wastewater collected and conveyed from our customers' residences and businesses, via our network of over 1,200 miles of sewers and more than 60 sewage pumping stations, as well as our H.L. Mooney AWRF, are designed, constructed, maintained, and operated to meet Federal Clean Water Act standards, the Occoquan (Watershed) Policy, Chesapeake Bay water quality standards, and the Virginia Sewage Collection and Treatment Regulations (SCAT Regulations per Title 12, Virginia Administrative Code Agency 5, Chapter 581).

Griffith Facility