Out of 68 ZIP codes with data in New Hampshire, these are the highest-ranked areas for recorded epa violations. See also: National ZIP Codes with Most EPA Water Violations | All New Hampshire Rankings
| Statistic | Value |
|---|---|
| ZIP codes ranked | 68 |
| Highest value | 25 |
| Median value | 3 |
| State | New Hampshire |
Top 68 Worst ZIP Codes
| Rank | ZIP Code | City | State | Recorded EPA Violations | Safety Score |
|---|---|---|---|---|---|
| 1 | 03054 | Merrimack | NH | 25 | 75/100 |
| 2 | 03813 | Center Conway | NH | 23 | — |
| 3 | 03818 | Conway | NH | 23 | — |
| 4 | 03860 | North Conway | NH | 23 | — |
| 5 | 03847 | Kearsarge | NH | 22 | — |
| 6 | 03229 | Contoocook | NH | 21 | 81/100 |
| 7 | 03048 | Greenville | NH | 17 | — |
| 8 | 03249 | Gilford | NH | 15 | — |
| 9 | 03045 | Goffstown | NH | 12 | — |
| 10 | 03832 | Eaton Center | NH | 11 | — |
| 11 | 03849 | Madison | NH | 11 | — |
| 12 | 03875 | Silver Lake | NH | 11 | — |
| 13 | 03748 | Enfield | NH | 8 | 82/100 |
| 14 | 03223 | Campton | NH | 6 | — |
| 15 | 03253 | Meredith | NH | 6 | — |
| 16 | 03842 | Hampton | NH | 6 | 64/100 |
| 17 | 03246 | Laconia | NH | 5 | 82/100 |
| 18 | 03774 | North Haverhill | NH | 5 | — |
| 19 | 03844 | Hampton Falls | NH | 5 | — |
| 20 | 03874 | Seabrook | NH | 5 | 65/100 |
| 21 | 03051 | Hudson | NH | 4 | 63/100 |
| 22 | 03244 | Hillsborough | NH | 4 | — |
| 23 | 03284 | Springfield | NH | 4 | — |
| 24 | 03753 | Grantham | NH | 4 | — |
| 25 | 03773 | Newport | NH | 4 | — |
| 26 | 03865 | Plaistow | NH | 4 | 64/100 |
| 27 | 03869 | Rollinsford | NH | 4 | — |
| 28 | 03870 | Rye | NH | 4 | 65/100 |
| 29 | 03871 | Rye Beach | NH | 4 | — |
| 30 | 03042 | Epping | NH | 3 | — |
| 31 | 03079 | Salem | NH | 3 | 65/100 |
| 32 | 03304 | Bow | NH | 3 | — |
| 33 | 03458 | Peterborough | NH | 3 | 82/100 |
| 34 | 03603 | Charlestown | NH | 3 | — |
| 35 | 03743 | Claremont | NH | 3 | — |
| 36 | 03819 | Danville | NH | 3 | — |
| 37 | 03038 | Derry | NH | 2 | 66/100 |
| 38 | 03053 | Londonderry | NH | 2 | 66/100 |
| 39 | 03055 | Milford | NH | 2 | 83/100 |
| 40 | 03087 | Windham | NH | 2 | 66/100 |
| 41 | 03862 | North Hampton | NH | 2 | 66/100 |
| 42 | 03867 | Rochester | NH | 2 | — |
| 43 | 03868 | Rochester | NH | 2 | — |
| 44 | 03885 | Stratham | NH | 2 | 66/100 |
| 45 | 03077 | Raymond | NH | 1 | 83/100 |
| 46 | 03217 | Ashland | NH | 1 | — |
| 47 | 03275 | Suncook | NH | 1 | 66/100 |
| 48 | 03276 | Tilton | NH | 1 | — |
| 49 | 03561 | Littleton | NH | 1 | 83/100 |
| 50 | 03570 | Berlin | NH | 1 | 83/100 |
| 51 | 03598 | Whitefield | NH | 1 | — |
| 52 | 03766 | Lebanon | NH | 1 | 83/100 |
| 53 | 03780 | Pike | NH | 1 | — |
| 54 | 03784 | West Lebanon | NH | 1 | 83/100 |
| 55 | 03785 | Woodsville | NH | 1 | — |
| 56 | 03801 | Portsmouth | NH | 1 | 66/100 |
| 57 | 03809 | Alton | NH | 1 | — |
| 58 | 03810 | Alton Bay | NH | 1 | — |
| 59 | 03811 | Atkinson | NH | 1 | 66/100 |
| 60 | 03814 | Center Ossipee | NH | 1 | — |
| 61 | 03820 | Dover | NH | 1 | — |
| 62 | 03823 | Madbury | NH | 1 | — |
| 63 | 03826 | East Hampstead | NH | 1 | — |
| 64 | 03833 | Exeter | NH | 1 | 67/100 |
| 65 | 03839 | Rochester | NH | 1 | — |
| 66 | 03841 | Hampstead | NH | 1 | 66/100 |
| 67 | 03854 | New Castle | NH | 1 | 66/100 |
| 68 | 03864 | Ossipee | NH | 1 | — |
Methodology
Violation counts include all types recorded in the EPA SDWIS database: Maximum Contaminant Level (MCL) violations, treatment technique violations, and monitoring/reporting violations. Both resolved and unresolved violations are counted. Higher counts may reflect longer system histories or larger service areas.
Data sources: EPA Safe Drinking Water Information System (SDWIS), FEMA National Flood Insurance Program, EPA radon zone maps, EIA electricity rates, and Consumer Confidence Reports. Last updated: 2026-08-31.
Frequently Asked Questions
What counts as an EPA water violation?
EPA violations include exceeding Maximum Contaminant Levels (MCLs), failing to treat water properly (treatment technique violations), and not testing or reporting on schedule (monitoring violations). Health-based violations are the most serious.
Does a high violation count mean the water is unsafe now?
Not necessarily. Many violations are historical or monitoring-related. However, a pattern of repeated violations indicates systemic issues with water system management or infrastructure.
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