Ledyard Water Hardness & Quality Report (2026)

Ledyard, Connecticut, in Southeastern Connecticut Planning Region — a southeast Connecticut town adjacent to Groton and Preston on the Thames River in southeast Connecticut — receives its water from the Ledyard Water Division, drawing from local reservoir sources (southeast Connecticut) through the southeast Connecticut distribution.

The very soft 22 mg/L hardness and very low TDS of 35.1 mg/L reflect the southeast Connecticut New England Upland's entirely insoluble crystalline basement — among the softest supplies in the entire Connecticut dataset. The southeast Connecticut watershed drains the New England Upland — Precambrian Sterling Plutonic Group (granite — insoluble), Precambrian Avalon Terrane (granite and gneiss — insoluble), and Ordovician metamorphic schist (insoluble). The entirely insoluble New England granite basement produces the very soft southeast Connecticut supply.

At 22 mg/L, Ledyard's water is very soft — essentially no scale forms, soap lathers abundantly, and appliances maintain excellent efficiency. Annual descaling is sufficient. The PFAS level of 5.2 ppt warrants a certified drinking water filter — Naval Submarine Base New London (Groton — AFFF, directly adjacent to Ledyard and the dominant southeast Connecticut PFAS source), and the Thames River submarine industrial corridor PFAS complex contribute to Ledyard's elevated readings despite the very soft water.