Staten Island Water Hardness & Quality Report (2026)

Staten Island is served by the New York City Department of Environmental Protection (NYC DEP) through the Richmond Tunnel System, which conveys the same Catskill–Delaware watershed water that supplies all five New York City boroughs. Water travels from the Catskill and Delaware reservoir systems through the Delaware Aqueduct, crosses under the Narrows via tunnel, and distributes throughout Staten Island's piped network. Although Staten Island historically had some local well sources in the Richmond Valley area, the modern municipal supply draws overwhelmingly from the NYC DEP gravity-fed surface reservoir system.

Staten Island tap water measures 36 mg/L — the same very soft classification as the rest of the New York City municipal system. The water originates from Devonian shale, siltstone, and Precambrian granitic gneiss bedrock in the Catskill and Delaware watersheds, which release minimal dissolved calcium and magnesium. Staten Island's position at the end of the distribution network does not materially alter the mineral chemistry of the water by the time it arrives at the tap.

At 36 mg/L, Staten Island residents experience the soft-water benefits common to all NYC boroughs: generous soap lather, virtually no limescale on appliances, and prolonged water heater and kettle lifespan compared to moderate or hard-water cities. As throughout New York City, the most practical water-quality concern for older homes is potential lead leaching from pre-1986 service lines and interior plumbing — running the cold tap for 30 seconds before drinking is the standard NYC DEP recommendation for buildings with potentially older pipes.