State rankings

New Hampshire water-system rankings

Community water systems in New Hampshire ranked by PurityRadar safety score — from EPA violations, enforcement, and PFAS data.

Lowest-scoring systems in New Hampshire

Ranked lowest score first. Population shown for context.

1 RYE WATER DIST RYE, NH · ~4,300 served 35 2 JAFFREY WATER WORKS JAFFREY, NH · ~3,800 served 47 3 HAMPSTEAD AREA WATER ATKINSON, NH · ~7,153 served 50 4 PORTSMOUTH WATER WORKS PORTSMOUTH, NH · ~33,000 served 59 5 HUDSON WATER DEPT HUDSON, NH · ~16,700 served 67 6 SEABROOK WATER DEPT SEABROOK, NH · ~14,000 served 68 7 EXETER WATER DEPT EXETER, NH · ~12,236 served 72 8 LITCHFIELD NASHUA, NH · ~7,000 served 75 9 PEMBROKE WATER WORKS PEMBROKE, NH · ~5,200 served 76 10 LONDONDERRY NASHUA, NH · ~6,255 served 77 11 SALEM WATER DEPT SALEM, NH · ~21,000 served 85 12 LITTLE POND ESTATES NASHUA, NH · ~3,000 served 85 13 MANCHESTER WATER WORKS MANCHESTER, NH · ~123,500 served 86 14 CENTRAL HOOKSETT WATER PCT HOOKSETT, NH · ~4,650 served 88 15 DERRY WATER DEPT DERRY, NH · ~17,290 served 91 16 PENNICHUCK WATER WORKS NASHUA, NH · ~89,073 served 100 17 CONCORD WATER DEPT CONCORD, NH · ~44,215 served 100 18 KEENE WATER DEPT KEENE, NH · ~30,000 served 100 19 DOVER WATER DEPT DOVER, NH · ~29,000 served 100 20 MERRIMACK VILLAGE DIST MERRIMACK, NH · ~25,500 served 100 21 ROCHESTER WATER DEPT ROCHESTER, NH · ~25,000 served 100 22 LACONIA WATER WORKS LACONIA, NH · ~17,000 served 100 23 UNH/DURHAM WATER SYS DURHAM, NH · ~16,000 served 100 24 LEBANON WATER DEPT LEBANON, NH · ~13,600 served 100 25 SOMERSWORTH WATER WORKS SOMERSWORTH, NH · ~12,000 served 100

Highest-scoring large systems in New Hampshire

Systems serving 10,000+ people with the best scores.

1 PENNICHUCK WATER WORKS NASHUA, NH · ~89,073 served 100 2 CONCORD WATER DEPT CONCORD, NH · ~44,215 served 100 3 KEENE WATER DEPT KEENE, NH · ~30,000 served 100 4 DOVER WATER DEPT DOVER, NH · ~29,000 served 100 5 MERRIMACK VILLAGE DIST MERRIMACK, NH · ~25,500 served 100 6 ROCHESTER WATER DEPT ROCHESTER, NH · ~25,000 served 100 7 LACONIA WATER WORKS LACONIA, NH · ~17,000 served 100 8 UNH/DURHAM WATER SYS DURHAM, NH · ~16,000 served 100
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Scores reflect EPA public records (violations, enforcement, PFAS), are system-level, and can’t account for your home’s plumbing. See the methodology.