New London Water Hardness & Quality Report (2026)

New London's water is supplied by the City of New London Department of Public Utilities, in partnership with Veolia Water for billing and operations. The primary source is Lake Konomoc, a reservoir located in the towns of Griswold and Voluntown, serving approximately 27,000 residents across New London County. Water is treated at the treatment facility near the lake using coagulation, sedimentation, filtration, and chlorination before distribution through the city's mains. No additional reservoirs or groundwater wells are noted as primary sources in available reports.

The Lake Konomoc watershed spans about 10 square miles of wooded uplands in the Thames River basin, with soils derived from glacial deposits over Avalonian metamorphic bedrock including Stonington Formation schists. The area's geology — Pleistocene glacial till, stratified drift, and granitic intrusions over low-carbonate metamorphic terrain — limits mineral pickup from calcium and magnesium-bearing rocks, producing a very soft, low-mineralised supply characteristic of New England surface waters. Runoff from granitic and metamorphic terrains keeps dissolved solids consistently low.

As soft water, New London's supply causes minimal scale buildup in pipes, heaters, and appliances, reducing maintenance needs for dishwashers, washing machines, and water heaters. However, corrosion may occur more readily in metal fixtures due to low buffering capacity, so using protective anode rods and periodic flushing is advised. A water softener is not recommended and could exacerbate corrosion or strip essential minerals. The 2021 Annual Water Quality Report confirms compliance with federal standards with no violations for lead or copper; no PFAS detections above limits were reported, and pH is typically neutral to slightly acidic.