Perth Amboy Water Hardness & Quality Report (2026)

Perth Amboy, New Jersey, the Middlesex County hub at the confluence of the Raritan River and Arthur Kill — one of New Jersey's most historic cities (the colonial capital of East Jersey), a major Middlesex County industrial waterfront and Latino community (one of the largest Puerto Rican-American and Dominican-American communities in New Jersey) — draws its municipal water supply from the Raritan River and Raritan Bay via the City of Perth Amboy Water Division. Water hardness in Perth Amboy measures 148 mg/L — classified as moderately hard.

Perth Amboy's moderate hardness reflects the Raritan River estuary's Middlesex County calcareous geology. The Raritan River at Perth Amboy–Raritan Bay drains the Raritan Bay watershed (calcareous Cretaceous Raritan Formation and Magothy Formation marine sand and clay of the New Jersey Coastal Plain — some calcareous contribution from the Cretaceous coastal plain formations). Perth Amboy's water system includes distribution infrastructure of the late 19th–early 20th century industrial era — the cast-iron mains from Perth Amboy's major industrial growth period. The aged distribution infrastructure, combined with the Raritan River supply, produces the moderate 148 mg/L at Perth Amboy.

At 148 mg/L, Perth Amboy residents encounter moderate scale accumulation. Faucet aerators and showerheads develop deposits after several months — monthly cleaning with citric acid solution is practical maintenance. City of Perth Amboy Water Division consistently delivers water meeting all New Jersey DEP and EPA Safe Drinking Water Act requirements.