Phillipsburg Water Hardness & Quality Report (2026)

Phillipsburg, New Jersey, in Warren County — a Warren County town adjacent to Easton Pennsylvania across the Delaware River in northwest New Jersey — receives its water from the Phillipsburg Water Division, drawing from the Delaware River (Warren County) through the northwest New Jersey water treatment system.

The moderately hard 150 mg/L hardness and TDS of 363.3 mg/L reflect the northwest New Jersey Delaware River supply's moderate Ridge-and-Valley calcareous character — consistent with the upper Delaware Valley communities across from Easton PA. The Delaware River at Warren County drains the New Jersey Ridge and Valley — Cambrian Kittatinny Mountain Quartzite (near-insoluble — dilutant), Ordovician Jacksonburg Limestone (calcareous — primary hardness contributor), Cambrian Allentown Dolomite (calcareous-dolomitic — secondary contributor), and Precambrian Reading Prong (insoluble). The Ordovician-Cambrian calcareous formations produce the moderately hard upper Delaware Valley supply.

At 150 mg/L, Phillipsburg's water is moderately hard — scale builds in kettles and appliances over months, dishwashers benefit from rinse aid, and faucet aerators need periodic cleaning. Quarterly descaling is appropriate. The PFAS level of 11.4 ppt warrants a certified reverse osmosis drinking water filter — McGuire Air Force Base (Burlington County — AFFF), Picatinny Arsenal (Morris County — AFFF), and the northwest New Jersey military industrial corridor contribute to Phillipsburg's very elevated readings.