Capitol Riverfront Water Hardness & Quality Report (2026)

Capitol Riverfront, in the District of Columbia — a DC neighborhood adjacent to the US Capitol and Navy Yard on the Anacostia River waterfront, a rapidly developing mixed-use district in southeast DC — receives its municipal water from DC Water, drawing from the Potomac River at the McMillan and Dalecarlia water treatment plants in northwest DC.

The moderately hard 113 mg/L hardness and TDS of 252.9 mg/L are essentially consistent with the broader DC Potomac supply — nearly identical to Petworth DC (119.5 mg/L, TDS 281) and Park View DC (118 mg/L), all receiving the same DC Water Potomac supply. The Potomac River at Washington DC drains the Blue Ridge (Precambrian Catoctin Formation metavolcanic) and the Great Valley carbonate zones, producing the moderately hard water characteristic of the DC municipal supply.

At 113 mg/L, Capitol Riverfront's water is moderately hard — scale builds in kettles and appliances over months, dishwashers benefit from rinse aid, and faucet aerators need periodic cleaning. Quarterly descaling is appropriate. The PFAS level of 7.5 ppt warrants a certified drinking water filter — Joint Base Anacostia-Bolling (AFFF user on the Anacostia waterfront), the Anacostia River PFAS industrial corridor, and the DC metro PFAS complex contribute to Capitol Riverfront's elevated readings.