Queens Water Hardness & Quality Report (2026)

Queens is served by the New York City Department of Environmental Protection (NYC DEP), which operates one of the largest unfiltered public water systems in the United States. Primary sources are the Catskill/Delaware watershed (providing over 90% of supply) and the Croton watershed. Water is delivered through the city's extensive distribution network serving Queens County and the other four boroughs. NYC DEP disinfects using UV exposure and chloramination rather than filtration, as the source water is exceptionally pure.

The Catskill/Delaware system drains the Catskill Mountains and Delaware River basin, flowing through Paleozoic sedimentary rocks and metamorphic formations that yield naturally soft water with low mineral content. The Croton watershed flows through more mineralized terrain and produces moderately hard water. The blended supply reflects this geological contrast, with water chemistry varying by neighborhood depending on which source predominates.

Queens residents generally experience soft water conditions (31 mg/L), which reduces scale buildup in pipes and appliances and minimizes soap scum. In areas where Croton water predominates, hardness can increase to moderately hard levels, potentially causing minor scale accumulation in water heaters and kettles. Most residents do not require water softeners, though those in heavily Croton-supplied areas may benefit from point-of-use treatment. The EWG identified six contaminants above health guidelines—Bromodichloromethane, Chloroform, Chromium-6, Dichloroacetic acid, Total trihalomethanes, and Trichloroacetic acid—all below EPA legal limits. Aging distribution pipes in older Queens neighborhoods may introduce lead and copper; residents are advised to run taps before use and consider point-of-use filters, especially in households with young children.