East New York Water Hardness & Quality Report (2026)

The New York City Department of Environmental Protection (DEP) operates the water utility serving East New York, Brooklyn, as part of the vast NYC water supply system. Water is sourced from three interconnected systems: the Catskill (including Ashokan and Schoharie Reservoirs), Delaware (including Pepacton, Neversink, and Cannonsville Reservoirs), and Croton (12 reservoirs and 3 controlled lakes, including New Croton Reservoir) watersheds, located up to 125 miles north in Ulster, Delaware, Greene, Schoharie, Sullivan, Putnam, Westchester, and Dutchess counties. The Catskill/Delaware system provides approximately 90% of supply while Croton contributes 10%, delivering 1–1.2 billion gallons daily to 8.5 million NYC residents. Distribution passes via aqueducts and tunnels to Hillview Reservoir before reaching the boroughs; citywide chemical and UV disinfection is applied with no local treatment plants required.

The 2,000-square-mile NYC watershed spans the Catskill/Delaware and Croton systems over protected forested uplands. The Catskill/Delaware geology features Paleozoic sedimentary rocks — Devonian shales, sandstones including the Catskill Formation, and minor limestones — over crystalline bedrock, promoting very soft water with low dissolved minerals. The Croton watershed overlies metamorphic gneisses, schists, and Precambrian granites of the Reading Prong, contributing similarly soft character. The absence of extensive carbonate aquifers limits calcium and magnesium, yielding pristine, low-mineralised surface water gravity-fed to the city.

NYC's soft water minimizes scale buildup in pipes, heaters, and appliances, reducing energy costs and maintenance needs. Kettles, dishwashers, and water heaters experience little limescale; soap lathers easily without excess detergent. No water softener is needed or recommended — occasional pipe flushing prevents minor sediment. pH typically ranges 6.8–8.0; the system consistently passes lead and copper rules via orthophosphate corrosion control. No notable PFAS exceedances in recent reports; turbidity remains below 0.3 NTU with zero Giardia/Cryptosporidium post-treatment. Catskill/Delaware water uses UV disinfection since 2013; Croton is filtered at the Crotonville plant. Annual DEP reports confirm full EPA compliance.