Middlesex Water Hardness & Quality Report (2026)

Middlesex Water Company serves over 470,000 people across Middlesex, Monmouth, and Ocean counties in central New Jersey. This utility draws its entire supply from 65 groundwater wells that tap into the New Jersey Coastal Plain aquifer system. Major wellfields include Colliers Mills, Shadow Lake, and Park Avenue. Water is treated at facilities like the Alexander D. Burr Memorial Plant in Edison and the Mickey Finn Treatment Plant in Old Bridge. Treatment processes involve disinfection, aeration to remove iron, and filtration. The company's service area covers roughly 125 square miles around the Raritan Bay region, with water originating from the New Jersey Coastal Plain watershed.

The water supply originates from the New Jersey Coastal Plain aquifer system, specifically the Englishtown aquifer formation and the Raritan Formation sands, both from the Cretaceous period. These formations are composed of unconsolidated quartz sands, gravels, silts, and clays. The sandy geology of the Coastal Plain, with limited contact with limestone or dolomite, results in a soft water supply naturally low in calcium and magnesium ions. Glacial outwash deposits in the northern parts of the Coastal Plain further dilute mineral content, leading to minimally mineralized groundwater.

Because the water is soft, homeowners in the Middlesex area will notice minimal scale buildup in pipes and appliances. This reduces the risk of damage to water heaters, dishwashers, and washing machines. Soap lathers easily, requiring less detergent, and fixtures are less likely to develop white deposits. A water softener isn't necessary given the low mineral content. Instead, regular flushing of water heaters to clear out any fine sediment from aquifer sands and checking aerators for particulates are recommended maintenance steps. Energy efficiency for heating water remains high without the insulating effect of scale.