Lynn Water Hardness & Quality Report (2026)

The Lynn Water and Sewer Commission (LWSC) provides drinking water to approximately 100,000 residents in Lynn, Essex County, Massachusetts, across a 13.7-square-mile area. Water is sourced from the Massachusetts Water Resources Authority (MWRA), which supplies surface water primarily from the Quabbin Reservoir and secondarily from the Wachusett Reservoir, both located in central Massachusetts. Treatment occurs at the John J. Carroll Water Treatment Plant in Marlborough, MA, applying coagulation, sedimentation, filtration, and disinfection before distribution via aqueducts to Lynn and surrounding communities.

The watershed encompasses the Quabbin and Wachusett basins within the Connecticut River drainage, protected by strict land use regulations to preserve water quality. Underlying geology consists of Precambrian and Paleozoic metamorphic rocks including mica schists and granitic intrusions, with thin glacial overburden from the Pleistocene epoch. This crystalline bedrock has low solubility and, combined with the absence of carbonate-rich limestones or dolomite, yields a naturally soft to moderately mineralized supply low in dissolved calcium and magnesium.

As a moderately mineralized supply, Lynn's water promotes moderate scale buildup in appliances like water heaters, dishwashers, and coffee makers, potentially reducing efficiency over time. Laundry may require slightly more detergent, and skin may feel drier after bathing. Deliming fixtures every 1–2 years and using scale inhibitors is advised. A water softener is recommended for households noticing spotting on glassware or film on fixtures. Chlorine is used for disinfection and may be noticeable in taste or odor. Lead concerns relate to home plumbing; flushing taps for 30 seconds to 2 minutes is advised, especially first thing in the morning. The MWRA's 2024 results confirm low levels of disinfection byproducts, radionuclides, and organics.