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

Out of 146 ZIP codes with data in New Hampshire, these are the highest-ranked areas for violations. See also: National ZIP Codes with Most EPA Water Violations | All New Hampshire Rankings

Statistic	Value
ZIP codes ranked	146
Highest value	33
Median value	3
State	New Hampshire

Top 100 Worst ZIP Codes

Rank	ZIP Code	City	State	Violations	Safety Score
1	03256	New Hampton	NH	33	33/100
2	03838	Glen	NH	27	15/100
3	03301	Concord	NH	21	53/100
4	03302	Concord	NH	21	58/100
5	03303	Concord	NH	21	53/100
6	03305	Concord	NH	21	50/100
7	03855	New Durham	NH	21	73/100
8	03216	Andover	NH	15	51/100
9	03823	Madbury	NH	15	46/100
10	03249	Gilford	NH	14	73/100
11	03741	Canaan	NH	14	52/100
12	03839	Rochester	NH	14	81/100
13	03866	Rochester	NH	14	81/100
14	03867	Rochester	NH	14	76/100
15	03868	Rochester	NH	14	81/100
16	03238	Glencliff	NH	12	49/100
17	03254	Moultonborough	NH	12	41/100
18	03281	Weare	NH	12	57/100
19	03047	Greenfield	NH	11	53/100
20	03279	Warren	NH	11	74/100
21	03307	Loudon	NH	11	40/100
22	03809	Alton	NH	11	55/100
23	03812	Bartlett	NH	11	60/100
24	03882	Effingham	NH	11	51/100
25	03304	Bow	NH	10	71/100
26	03042	Epping	NH	9	50/100
27	03101	Manchester	NH	9	80/100
28	03102	Manchester	NH	9	75/100
29	03103	Manchester	NH	9	75/100
30	03104	Manchester	NH	9	75/100
31	03105	Manchester	NH	9	79/100
32	03107	Manchester	NH	9	79/100
33	03108	Manchester	NH	9	79/100
34	03109	Manchester	NH	9	80/100
35	03111	Manchester	NH	9	79/100
36	03229	Contoocook	NH	9	72/100
37	03771	Monroe	NH	9	78/100
38	03811	Atkinson	NH	9	66/100
39	03885	Stratham	NH	9	55/100
40	03077	Raymond	NH	8	70/100
41	03748	Enfield	NH	8	70/100
42	03849	Madison	NH	8	12/100
43	03048	Greenville	NH	7	55/100
44	03608	Walpole	NH	7	69/100
45	03886	Tamworth	NH	7	43/100
46	03045	Goffstown	NH	6	62/100
47	03076	Pelham	NH	6	62/100
48	03253	Meredith	NH	6	78/100
49	03818	Conway	NH	6	59/100
50	03874	Seabrook	NH	6	70/100
51	03053	Londonderry	NH	5	76/100
52	03079	Salem	NH	5	69/100
53	03234	Epsom	NH	5	65/100
54	03289	Winnisquam	NH	5	70/100
55	03470	Winchester	NH	5	69/100
56	03580	Franconia	NH	5	56/100
57	03816	Center Tuftonboro	NH	5	31/100
58	03842	Hampton	NH	5	67/100
59	03843	Hampton	NH	5	82/100
60	03275	Suncook	NH	4	64/100
61	03574	Bethlehem	NH	4	52/100
62	03753	Grantham	NH	4	76/100
63	03765	Haverhill	NH	4	73/100
64	03819	Danville	NH	4	70/100
65	03826	East Hampstead	NH	4	70/100
66	03846	Jackson	NH	4	59/100
67	03860	North Conway	NH	4	63/100
68	03864	Ossipee	NH	4	38/100
69	03865	Plaistow	NH	4	65/100
70	03223	Campton	NH	3	52/100
71	03244	Hillsborough	NH	3	69/100
72	03266	Rumney	NH	3	49/100
73	03278	Warner	NH	3	74/100
74	03452	Jaffrey	NH	3	71/100
75	03774	North Haverhill	NH	3	71/100
76	03801	Portsmouth	NH	3	77/100
77	03802	Portsmouth	NH	3	82/100
78	03803	Portsmouth	NH	3	82/100
79	03804	Portsmouth	NH	3	82/100
80	03814	Center Ossipee	NH	3	34/100
81	03817	Chocorua	NH	3	53/100
82	03845	Intervale	NH	3	69/100
83	03869	Rollinsford	NH	3	40/100
84	03034	Candia	NH	2	74/100
85	03049	Hollis	NH	2	73/100
86	03054	Merrimack	NH	2	72/100
87	03055	Milford	NH	2	82/100
88	03071	New Ipswich	NH	2	74/100
89	03245	Holderness	NH	2	47/100
90	03255	Newbury	NH	2	57/100
91	03261	Northwood	NH	2	73/100
92	03264	Plymouth	NH	2	77/100
93	03276	Tilton	NH	2	69/100
94	03298	Tilton	NH	2	71/100
95	03299	Tilton	NH	2	71/100
96	03458	Peterborough	NH	2	67/100
97	03576	Colebrook	NH	2	74/100
98	03585	Lisbon	NH	2	69/100
99	03756	Lebanon	NH	2	78/100
100	03766	Lebanon	NH	2	74/100

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: 2026-06-04.

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.