Piscataway Water Hardness & Quality Report (2026)

Piscataway, NJ, receives its drinking water from the Middlesex Water Company, a public utility serving Middlesex County and surrounding communities across central New Jersey. Surface water is sourced primarily from the Raritan River Valley reservoirs, including Spruce Run and Round Valley Reservoirs managed in partnership with the state, as well as intakes from the Delaware and Raritan Canal. Treatment occurs at the Park Avenue Treatment Plant in South Plainfield and the Robert J. Fehnel Plant, using coagulation with alum, settling, dual-media filtration, chloramination, and fluoride addition. The service area covers over 500,000 residents across 50+ communities in central New Jersey.

The water originates from the Raritan River Watershed, spanning 1,100 square miles with tributaries draining from the Watchung Mountains and Piedmont Province. Underlying geology consists of Mesozoic-era sedimentary formations including the Stockton and Lockatong Formations—sandstones, shales, and mudstones—interspersed with diabase intrusions, alongside carbonate rocks of the Passaic Formation. These formations contribute moderate dissolved calcium and magnesium, producing a moderately hard supply typical of surface runoff over limestone-influenced terrain, without the extreme hardness of deep groundwater sources.

As moderately hard water, Piscataway's supply promotes scale buildup in water heaters, dishwashers, and washing machines, reducing efficiency over time and causing white deposits on fixtures and kettles. Higher detergent use is needed for lathering. Maintenance involves periodic vinegar descaling, installing drain screens, and flushing heaters annually; a water softener is recommended for households noticing soap scum, dry skin, or rising energy bills. Water quality is EPA compliant with pH ranging 7.0–8.5; lead and copper rules are met via corrosion control, no notable PFAS exceedances have been reported, and occasional iron or manganese fluctuations are addressed via oxidation-filtration.