West Falls Church Water Hardness & Quality Report (2026)

West Falls Church, Virginia is served by Fairfax Water, the primary utility providing drinking water to Fairfax County and surrounding communities including this area. The main sources are the Potomac River, drawing from the Washington Aqueduct and Fairfax Water's own intake, and the Occoquan Reservoir impounded on the Occoquan River. Treatment is carried out at the Corbalis Treatment Plant and Griffith Treatment Plant, which apply coagulation, sedimentation, filtration, and disinfection before distributing water to over 2 million residents in Northern Virginia.

The Potomac River watershed spans 14,670 square miles across four states and the District of Columbia, with headwaters in the Appalachian Mountains flowing over folded metamorphic rocks of the Blue Ridge and Piedmont before reaching the Coastal Plain. The Occoquan Reservoir lies within the Triassic Culpeper Basin, underlain by red beds, sandstones, and volcanics of the Newark Supergroup. Contact with carbonate-bearing formations including the Conococheague Limestone (Cambrian) and dolomitic limestones in tributaries imparts a moderately mineralized character to raw water, though rainfall dilution and blending moderate the mineral load to yield a soft profile in distribution.

As a soft water supply, scale buildup is minimal, posing little risk to dishwashers, water heaters, and coffee makers. Routine descaling is rarely needed and water softeners are not recommended, allowing standard detergents and soaps to perform optimally without excess usage. Fairfax Water maintains EPA compliance with pH typically between 7.2–8.0; lead and copper levels are well below action limits through corrosion control; trace PFAS detections are managed via granular activated carbon; and chloramination combined with UV provides redundant residual disinfection.