Keene Water Hardness & Quality Report (2026)

Keene, New Hampshire, in Cheshire County in the western Connecticut River valley region — the economic and cultural hub of southwestern New Hampshire near Mount Monadnock and the Ashuelot River corridor — receives its municipal water from the City of Keene Water Utility, drawing from local reservoir impoundments in the Monadnock Region highlands fed by the Ashuelot River watershed. Keene's reservoir system captures water from the forested hills surrounding this classic New England college city.

The very soft 27 mg/L hardness and low TDS of 47.2 mg/L reflect the Monadnock Region's classic New Hampshire granite geology. The Ashuelot River watershed drains the Cheshire Hills and Monadnock area — a rugged upland of Devonian and Carboniferous Acadian-age granites, Silurian and Devonian metamorphic schists and gneisses, and various Mesozoic intrusive igneous rocks that give New Hampshire its nickname as the Granite State. These ancient crystalline terrains have essentially no soluble carbonate minerals, and the abundant precipitation from the region's humid continental climate drains rapidly through the rocky uplands into Keene's reservoir system with minimal mineral pickup.

At 27 mg/L, Keene's water is very soft — excellent for all household applications. Soap lathers abundantly, appliances scale very slowly over many months, and the dishwasher produces spotless glassware without special treatment. Annual descaling of kettles and coffee machines is typically adequate. The primary consideration with this soft water is its mildly corrosive tendency — very soft New Hampshire water at TDS 47.2 has low buffering capacity. Residents in homes with older copper plumbing should flush cold taps before morning drinking. The PFAS level of 4.5 ppt is moderate — the Cheshire County corridor has some PFAS contributions from the region's light industrial activity and historic landfill sites.