Millburn Water Hardness & Quality Report (2026)

New Jersey American Water operates the Short Hills System, serving Millburn in Essex County, New Jersey, with a population of approximately 20,000 residents across Short Hills, Summit, and adjacent areas. The primary sources are surface water reservoirs including Canoe Brook Reservoir and related impoundments in the upper Passaic River basin. Water is treated at the Short Hills Treatment Plant, employing filtration, disinfection, and pH adjustment before distribution through a network of mains covering about 15 square miles.

The supply originates in the Passaic River watershed, encompassing the Watchung Mountains and Piedmont physiographic province. Triassic sedimentary rocks dominate — including red beds of the Brunswick Group with interbedded shales and sandstones — alongside Jurassic diabase sills. These formations release minerals into infiltrating rainwater, yielding a supply with elevated calcium and magnesium from geological dissolution. Reservoir storage allows mineral equilibration, shaping the moderately mineralized character without significant groundwater aquifer reliance.

Hard water in this range leads to scale buildup in appliances like water heaters, dishwashers, and washing machines, reducing efficiency and increasing energy costs. Faucets and fixtures develop stubborn spots, while laundry feels stiff and soap lathers poorly. Regular vinegar descaling and low-flow aerators help mitigate effects; a whole-house water softener is recommended for households with frequent scaling issues. The system meets lead (90th percentile 2 µg/L, action level 15 µg/L) and copper (0.249 mg/L, action level 1.3 mg/L) standards, with total hardness ranging 80–240 mg/L as CaCO3 and treatment including coagulation, sedimentation, filtration, and chlorination per the 2025 CCR from New Jersey American Water.