Anacostia Water Hardness & Quality Report (2026)

DC Water is the main utility providing drinking water to more than 700,000 residents in Anacostia, Washington, D.C. The Potomac River serves as the source, with water drawn from intakes at Great Falls and Little Falls by the Washington Aqueduct. This facility treats the water through a comprehensive process involving coagulation, sedimentation, filtration, fluoridation, pH adjustment, and disinfection. The treated water then travels through a 1,300-mile distribution network to reach all neighborhoods, including Anacostia.

The Potomac River watershed, spanning 14,670 square miles from the Appalachian Mountains to Washington, D.C., traverses diverse geological terrains. Upstream, Paleozoic sedimentary rocks like limestone and shale are prevalent in the Valley & Ridge province. As the river flows towards Washington, D.C., it passes through the Piedmont region, characterized by crystalline metamorphic rocks. These upstream formations, particularly the limestone and dolomite outcrops, release calcium and magnesium ions into the water, resulting in a moderately mineralized supply that fluctuates seasonally.

This moderately hard water supply can lead to limescale buildup in household plumbing and appliances, potentially decreasing the efficiency and lifespan of items like water heaters and dishwashers. You might also notice spotting on glassware or soap scum in showers, especially during months with higher mineral content. To manage these effects, homeowners can regularly descale appliances and consider using vinegar rinses. For persistent issues and improved cleaning effectiveness, installing a water softener is often a beneficial solution. DC Water consistently meets or exceeds EPA standards, ensuring the water's safety through extensive annual testing.