ZIP Codes with Most EPA Violations in New Hampshire ...

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.