Gloucester Water Hardness & Quality Report (2026)

The City of Gloucester Department of Public Works (DPW) operates the public water system (MassDEP PWS ID #3107000), serving approximately 28,000 residents across the city of Gloucester in Essex County, Massachusetts, with some supply extending to adjacent areas in Manchester-by-the-Sea. Water is sourced exclusively from three surface reservoirs: Babson Reservoir, McPherson Reservoir, and Griffith Reservoir. Treatment occurs at the DPW's Water Treatment Plant on Reservoir Road, where conventional filtration, disinfection, and corrosion control are applied before distribution through approximately 150 miles of mains.

The reservoirs lie within the Ipswich River watershed, a coastal New England basin draining into Ipswich Bay. Underlying geology features Avalonian terrane metamorphic rocks from the Devonian to Carboniferous periods, including the Mattapan Volcanic Complex and Roxbury Conglomerate — felsic volcanics and quartzites with minimal sedimentary carbonates. No major limestone aquifers are present; thin Pleistocene glacial drift over fractured bedrock limits mineral leaching, imparting a soft water character with low dissolved solids and minimal natural mineralization from source rocks.

Soft water minimizes scale buildup on fixtures, appliances, and plumbing, reducing maintenance needs for water heaters, dishwashers, and washing machines. Soap and detergents lather easily without residue. No water softener is recommended or needed — excessive softening could introduce sodium unnecessarily. Monitor for potential pipe corrosion from low mineral buffering. pH is typically 7.0–8.5 post-treatment; the system complies with the Lead and Copper Rule via orthophosphate corrosion inhibitors. No notable PFAS detections above limits; primary contaminants of concern are TTHMs (below MCLs) and trace iron/manganese. Treatment includes coagulation, sedimentation, dual-media filtration, chlorination, and fluoride addition.