Sheepshead Bay Water Hardness & Quality Report (2026)

New York City Department of Environmental Protection (DEP) provides water to Sheepshead Bay in Brooklyn, serving over 8 million people in the five boroughs and parts of Westchester County. Primary sources are the Catskill/Delaware systems (90%), including Ashokan, Schoharie, Rondout, and Neversink reservoirs, supplemented by the Croton system (10%) with 12 smaller reservoirs and three controlled lakes. Water travels via 100+ miles of aqueducts to treatment facilities including the Croton and Catskill/Delaware Ultraviolet (UV) Disinfection Facilities, then through city tunnels for distribution.

The 2,000-square-mile watershed spans the Catskill Mountains and Hudson Valley, underlain by ancient Devonian-age sedimentary rocks — including shales, sandstones, and greywackes — with limited carbonate formations. Glacial deposits influence surficial hydrology, but the predominantly siliceous bedrock yields moderately mineralized water with naturally low alkalinity and mineral content. This geology imparts a soft to moderately hard character, distinct from calcium-rich groundwater found in carbonate terrains, resulting in a supply low in dissolved calcium and magnesium compared to limestone-dominated aquifer systems elsewhere.

Moderately hard water in Sheepshead Bay promotes moderate scale buildup in appliances like dishwashers, water heaters, and coffee makers, reducing efficiency over time and spotting glassware; dry skin or soap scum may also occur. Routine maintenance includes quarterly vinegar descaling and using rinse aids; a water softener is optional but recommended for heavy appliance users to extend lifespan and improve lathering. NYC water maintains pH 6.5–8.5 per DEP reports, with lead/copper compliance achieved through corrosion control and pipe replacement programs, though legacy building pipes pose localized risks. No PFAS exceedances have been noted in recent reports, and treatment at the Hillview and Croton plants involves UV disinfection, chlorination, and fluoridation.