Long Island City Water Hardness & Quality Report (2026)

Long Island City, in the borough of Queens, New York, receives its municipal water from the New York City Department of Environmental Protection (DEP), which operates the city's celebrated unfiltered surface water system. Supply is drawn from the Catskill/Delaware Watershed — nineteen reservoirs impounding snowmelt from the Catskill Mountains and Delaware River headwaters — and blended with harder water from the Croton Watershed system in Westchester County. Water reaches Long Island City through the City Water Tunnel No. 2 and borough distribution mains, serving this rapidly developed western Queens neighborhood.

The moderate 120 mg/L hardness reflects a higher proportion of Croton Watershed blending in this part of Queens compared to softer neighborhoods in the outer boroughs. Croton source water contacts Ordovician and Cambrian limestone and dolomite formations in the Hudson Valley and Westchester uplands, picking up additional calcium and magnesium bicarbonates compared to the softer Catskill-only supply. The resulting blend sits noticeably harder than the classic New York City water profile known from Manhattan and upper Brooklyn.

At 120 mg/L, Long Island City residents experience moderately hard water — a step up from the rest of the city. Some white scale may appear inside kettles after weeks of use, and glassware from the dishwasher may show occasional mineral film. Soap lathers adequately without softening, and showerhead clogging is uncommon at this level. Quarterly descaling of kettles and coffee machines keeps them performing well. As in all pre-1986 New York buildings, residents should flush cold taps for 30 seconds before drinking first-draw water as a precaution against legacy lead plumbing materials in older distribution infrastructure.