Rahway Water Hardness & Quality Report (2026)

Rahway Water Department serves the city of Rahway in Union County, New Jersey, providing drinking water to over 30,000 residents via surface water sources. The primary supply originates from the Rahway River Watershed, with intake from the Rahway River main stem and its tributaries draining approximately 83 square miles across Union and Middlesex counties. Water is treated at the department's facilities using standard municipal processes — coagulation, sedimentation, filtration, and disinfection — to meet EPA and state drinking water standards. The utility can be reached at 732-388-0086 or PO Box 1885, Rahway, NJ 07065.

The Rahway River Watershed spans urban and suburban areas of central New Jersey, underlain by Triassic and Jurassic bedrock of the Brunswick Group — sandstones and shales rich in calcium and magnesium-bearing minerals — overlain by Pleistocene glacial till and outwash deposits. These sedimentary formations release calcium and magnesium ions as runoff and streamflow weather the rock, yielding a hard supply. The Piedmont physiographic province setting promotes natural mineralization through weathering, resulting in elevated dissolved solids. Non-point source pollution from urban runoff is monitored by the Rahway River Stream Team.

Hard water in Rahway leads to scale buildup in appliances such as water heaters, dishwashers, coffee makers, and washing machines, reducing efficiency and lifespan. White residue on fixtures, reduced soap lathering, and spotted dishes are common signs. Maintenance tips include regular vinegar descaling, installing sediment filters, and checking hot water heater dip tubes for degradation. A whole-house water softener is recommended to prevent scaling and extend appliance life. The 2026 water quality report indicates 6 contaminants exceeded EPA health-based guidelines in at least one location served, though the utility reports overall compliance with EPA standards in its annual Consumer Confidence Report.