Brightwood Water Hardness & Quality Report (2026)

DC Water (District of Columbia Water and Sewer Authority) provides water service to Brightwood and all of Washington, D.C., sourcing primarily from the Potomac River via the Washington Aqueduct, a U.S. Army Corps of Engineers facility. Raw water is drawn from two intakes on the Potomac River in Fairfax County, Virginia, and treated at the Dalecarlia and Potomac River Water Treatment Plants before distribution through 1,300 miles of pipes to over 700,000 District residents. No separate utility exists for Brightwood; all tap water is managed exclusively by DC Water.

The Potomac River watershed spans 14,670 square miles across West Virginia, Virginia, Maryland, and D.C., draining Appalachian highlands into the Chesapeake Bay. Underlying geology transitions from Paleozoic metamorphic rocks in the upper basin to Mesozoic and Cenozoic Coastal Plain sediments downstream, including the Potomac Group aquifer with sand, gravel, and clay layers. This mixed lithology imparts a moderately mineralized character through natural dissolution of carbonates, with seasonal variations influenced by river flow, tributary inputs, and urban runoff from upstream agriculture.

Moderately hard water at 126 mg/L causes moderate scale buildup in dishwashers, washing machines, and water heaters, with noticeable spotting on glassware and soap scum in showers, especially during warmer months when hardness peaks. Kettles and faucets develop limescale over time; monthly vinegar descaling and detergent boosters help maintain appliances. A water softener is often recommended for households with hard water concerns. DC Water's 2025 CCR reports pH stable at 7.2–8.0, no lead action exceedances (90th percentile 3 ppb), total hardness 78–175 ppm, and no PFAS violations; treatment includes coagulation, sedimentation, filtration, chloramination, and fluoride addition.