Derry Village Water Hardness & Quality Report (2026)

Derry Village (Derry), New Hampshire, in Rockingham County — a major south New Hampshire community (Derry is one of the largest towns in New Hampshire — a major south New Hampshire community in the Manchester–Nashua–Portsmouth suburban triangle), home of Robert Frost Farm (the New Hampshire farm where American poet Robert Frost lived from 1900–1911 — the Derry farm period was one of the most creative in Frost's career, producing many of the poems in his first two collections; the Robert Frost Farm State Historic Site is a major Derry landmark), home of Taylor's Mill (a historic New Hampshire mill complex), a diverse Rockingham County community with a significant Irish-American, French-Canadian, and working-class professional population, and adjacent to Manchester in the south New Hampshire growth corridor — draws its municipal water supply via the Pennichuck Water Works or Derry Village system. Water hardness in Derry Village measures 18.5 mg/L — classified as extremely soft.

Derry Village's extremely soft supply reflects the south New Hampshire Rockingham County watershed's highly calcareous-poor crystalline geology. The Rockingham County glacial outwash aquifer at Derry draws from: the Precambrian–Paleozoic White Mountain Granite (calcareous-poor — virtually no dissolved calcium carbonate); the Devonian–Mississippian Hillsborough County gneiss and schist (calcareous-poor); and the Wisconsin Age calcareous-poor New England glacial outwash (minimal carbonate content — New England glacial outwash from granite-dominated terrain). The calcareous-poor New Hampshire granite watershed produces the extremely soft 18.5 mg/L.

With hardness at 18.5 mg/L, Derry Village residents enjoy extremely soft water. Pennichuck Water Works consistently delivers water meeting all New Hampshire DES and EPA Safe Drinking Water Act requirements.