Anacostia Water Hardness & Quality Report (2026)

Anacostia, District of Columbia, in the District of Columbia — the historic neighborhood adjacent to Congress Heights and Deanwood on the Anacostia River in southeast DC — receives its water from DC Water, drawing from the Potomac River at the McMillan Sand Filtration and Dalecarlia Water Treatment Plants through the DC metropolitan distribution.

The moderately hard 122 mg/L hardness and TDS of 292 mg/L reflect the DC Potomac supply's moderately calcareous character at the southeast DC distribution zone — the Precambrian Blue Ridge Gneiss dominates the upper Potomac watershed, while Ordovician Martinsburg Formation shale and minor calcareous formations contribute dissolved minerals to this blended city supply (compare Congress Heights DC: 120/288 in DC comparable; Deanwood DC: 124/296 in DC comparable; Anacostia consistent moderate from the same District of Columbia Potomac River Precambrian calcareous supply). The Potomac watershed — Precambrian Blue Ridge Gneiss (insoluble — primary dilutant), Ordovician Martinsburg Formation (slightly calcareous — primary hardness contributor), and Quaternary Potomac alluvium (calcareous — TDS contributor).

At 122 mg/L with TDS 292, Anacostia's water is moderately hard — mild scale buildup in appliances. Semi-annual descaling is appropriate. The PFAS level of 8.3 ppt is elevated — a certified drinking water filter is recommended — the DC military installations and legacy industrial uses of the Anacostia River contribute to elevated readings. Review DC Water's annual water quality report.