Glastonbury Water Hardness & Quality Report (2026)

Glastonbury, Connecticut receives drinking water from the Metropolitan District Commission (MDC), a regional utility serving 390,887 people including Glastonbury Center. Water originates entirely from surface reservoirs: the 30-billion-gallon Barkhamsted Reservoir on the East Branch of the Farmington River, impounded by Saville Dam east of New Hartford, and the 9-billion-gallon Nepaug Reservoir on the Nepaug River tributary, bounded by Phelps Brook and Nepaug Dams northwest of Collinsville. Treatment at MDC facilities involves conventional coagulation, sedimentation, filtration, and disinfection across a protected watershed spanning 89.7 square miles of forested uplands in the Farmington River basin.

The MDC watershed is underlain by Paleozoic metamorphic rocks—schists and gneisses—interspersed with granitic intrusions and limestone outcrops from the Ordovician-Devonian periods, overlain by glacial deposits. As rainwater and snowmelt percolate through soils, fractured bedrock, and limestone-bearing tributary drainage in Connecticut's Piedmont-like terrain, they dissolve calcium and magnesium ions into the supply. This mineral uptake, characteristic of New England surface supplies influenced by carbonate-bearing geology and glacial till, results in a hard water character without the moderating effect of peat or conifer soils.

Hard water in this range promotes limescale buildup in pipes, heaters, dishwashers, and washing machines, reducing efficiency by 20–30% over time and increasing energy bills. Kettles and fixtures accumulate white deposits first; coffee makers and humidifiers clog next. Monthly vinegar descaling, sediment pre-filters, and annual plumber checks for galvanized pipes are recommended, and a water softener is strongly advised—especially above the 7 GPG threshold noted regionally. MDC water meets EPA standards, with no PFAS detected in 2023 UCMR5 testing; fluoride is present below the 4 ppm limit, and the water should be flushed 30–120 seconds if stagnant to minimize lead risk from old plumbing.