Manchester Water Hardness & Quality Report (2026)

Manchester Water Works serves the city of Manchester and surrounding municipalities in Hillsborough County, New Hampshire. The utility has historically sourced water from Lake Massabesic, a protected surface water body treated at a local water treatment plant. Recent infrastructure changes include plans to supplement supply with water from the Merrimack River and new groundwater collection sites to meet growing demand. Annual Water Quality Reports are published each April on the city's website; the utility treats water to meet Safe Drinking Water Act standards throughout its distribution system.

The Manchester water supply area is underlain by Precambrian granite, gneiss, and other metamorphic rocks typical of central New Hampshire. Lake Massabesic sits within a watershed dominated by these hard, crystalline formations, which are relatively insoluble and contribute minimal dissolved minerals, producing a naturally soft supply. Planned groundwater sources from the Merrimack River valley may introduce slightly higher mineral content, but the overall supply remains soft due to the region's geological character of impermeable, low-solubility bedrock.

At soft hardness levels, Manchester residents experience minimal scale buildup in appliances and water heaters, and soap lathers readily; water softening is generally unnecessary. More pressing concerns include statewide PFAS contamination (carcinogenic per- and polyfluoroalkyl substances), naturally occurring radium and chromium in groundwater, and trace aluminum, barium, chlorate, fluoride, and manganese. Aging infrastructure allows combined stormwater and sewage overflow into the Merrimack River during heavy rain, and bacterial contamination has historically reached five times EPA-allowed levels; water is treated to meet Safe Drinking Water Act standards, though ongoing infrastructure challenges remain.