Cromwell Water Hardness & Quality Report (2026)

Cromwell, Connecticut, in Middlesex County — a Middlesex County town adjacent to Middletown and Rocky Hill on the Connecticut River in central Connecticut — receives its water from the Cromwell Water Division or Connecticut Water, drawing from the Connecticut River or local reservoirs (Middlesex County) through the central Connecticut distribution.

The moderately hard 99.5 mg/L hardness and TDS of 261.2 mg/L reflect the central Connecticut Middlesex County Connecticut Valley supply's moderate calcareous character — reflecting the Triassic Hartford Basin's slightly calcareous arkose sedimentary geology that provides moderate mineral dissolution, typical of the central Connecticut River Valley communities. The Connecticut River at Middlesex County — Triassic Hartford Arkose (slightly calcareous — primary hardness contributor), Jurassic trap rock (insoluble — dilutant), and Precambrian Eastern Highlands gneiss (insoluble — dilutant from upland tributaries).

At 99.5 mg/L, Cromwell's water is moderately hard — light scale forms slowly in appliances, dishwashers benefit from rinse aid, and faucet aerators need occasional cleaning. Semi-annual descaling is appropriate. The PFAS level of 11.9 ppt warrants a certified reverse osmosis drinking water filter — Bradley International Airport (Hartford County — AFFF) and the central Connecticut industrial corridor contribute significantly to Cromwell's very elevated readings.