Unionport Water Hardness & Quality Report (2026)

Unionport, New York, in the Bronx in New York City's northernmost borough, receives its municipal water from the New York City Department of Environmental Protection (NYC DEP), which supplies the entire city from the Catskill-Delaware Watershed — one of the largest unfiltered surface water supply systems in the world. The Catskill system draws from Schoharie, Ashokan, Rondout, and Neversink reservoirs in the Catskill Mountains and Delaware County uplands of New York State, while the Delaware system adds the Cannonsville, Pepacton, and Downsville reservoirs on Delaware River tributaries.

The soft 64 mg/L hardness and very low TDS of 96.4 mg/L are characteristic of the NYC Catskill-Delaware water supply — one of the most celebrated water systems in the United States. The watershed reservoirs collect runoff from the Catskill Mountains and Allegheny Plateau uplands — regions of Devonian and Silurian shale, sandstone, and siltstone, along with portions of the Taconic metamorphic belt and Acadian orogenic terrain — all siliciclastic and crystalline rocks with negligible carbonate content. NYC DEP has preserved these watersheds through extensive land acquisition programs, protecting them from development that would degrade the pristine soft water character.

At 64 mg/L, Unionport receives the soft, clean water that is a hallmark of New York City — one of the few large US cities with unfiltered water. Soap lathers abundantly, appliances scale very slowly, and glassware from the dishwasher is spotless. Annual descaling of kettles and coffee machines is typically sufficient. The primary concern is the PFAS level of 3.2 ppt — very low for a major metropolitan area, reflecting NYC DEP's aggressive watershed protection. NYC's tap water is widely considered among the finest in the country.