Lynn Water Hardness & Quality Report (2026)

Lynn, Massachusetts, a historic shoe-manufacturing city in Essex County north of Boston, draws its municipal water supply through the Lynn Water and Sewer Commission, sourcing from the Saugus River Watershed reservoirs — Birch Meadow Reservoir and Breed's Pond in Lynn and Saugus — and through interconnections with the Massachusetts Water Resources Authority (MWRA) system for supplemental supply. The Saugus River watershed drains the north shore Massachusetts coastal plain and Beverly–Marblehead Rocky Hills area. Water hardness measures 107 mg/L — classified as moderately hard.

Lynn's moderate hardness reflects the complex geology of the Saugus River watershed and the north shore Massachusetts coastal plain. The watershed drains the Lynn Volcanic Complex — Precambrian Lynn Volcanics (ancient igneous volcanic and pyroclastic rocks of the Lynn–Salem volcanic arc), Salem Granodiorite (Precambrian intrusive), and Marblehead Syenite (alkali-rich Precambrian intrusive). These ancient volcanic and plutonic rocks of the north shore Massachusetts Avalonian terrane contain various calcium-bearing minerals (plagioclase feldspar in the volcanics, calcic amphibole in the granodiorite) that contribute modest but detectable dissolved calcium to watershed drainage — somewhat more than the purely granitic Wachusett watershed.

With hardness at 107 mg/L, Lynn residents encounter moderate scale accumulation. Faucet aerators and showerheads develop deposits after several months — monthly cleaning with citric acid solution is practical maintenance. Dishwashers produce clean glassware with moderate rinse-aid use. Lynn Water and Sewer Commission consistently delivers water meeting all Massachusetts DEP and EPA Safe Drinking Water Act requirements.