Private well water testing in New Hampshire, by county
NHDES says private wells are the main source of drinking water for roughly 46% of New Hampshire's population, and that the state has no statewide testing or treatment requirement for private wells (some towns require testing).[1]
County guides
- Rockingham County Last verified 2026-10-25
Arsenic and radon are the big issues: in state lab data, 31% of Rockingham County wells tested were over 5 µg/L arsenic and 32% over the 2,000 pCi/L radon advisory. The state lab c...