West Hartford Water Hardness & Quality Report (2026)

West Hartford, Connecticut, in Hartford County west of Hartford — one of Connecticut's most affluent and desirable towns, home of the University of Hartford and the Mark Twain Museum — draws its municipal water supply from the Barkhamsted Reservoir (on the East Branch of the Farmington River in Litchfield County) via the Metropolitan District Commission (MDC) of Hartford County, treating high-quality Farmington River reservoir water for the greater Hartford area including West Hartford. Water hardness in West Hartford measures 23 mg/L — classified as extremely soft, among the softest municipal water supplies in the United States.

West Hartford's extraordinarily soft supply reflects the Barkhamsted Reservoir watershed's exceptional crystalline geology in the Connecticut Western Highlands. The East Branch Farmington River watershed at Barkhamsted drains: the Precambrian Rowe–Hawley schist zone (calcium-poor metamorphic schist — Proterozoic); the Cambrian Hoosac Formation (quartz–feldspar–mica schist — siliceous); the Ordovician Hartland Formation (amphibolite and quartzite — calcium-poor); and the Carboniferous Brimfield Schist (mica schist and quartzite). These highly siliceous metamorphic terranes of the Connecticut Western Highlands Basement dissolve extremely slowly in the cool, humid New England climate, producing some of the softest natural water in the continental United States. The 23 mg/L ranks among the softest municipal supplies in the country.

With hardness at 23 mg/L, West Hartford residents experience essentially no scale from their extremely soft water. However, extremely soft water can be mildly corrosive to copper plumbing — the MDC adjusts pH to prevent corrosion. Metropolitan District Commission consistently delivers water meeting all Connecticut DEEP and EPA Safe Drinking Water Act requirements.