2026 Rankings

Worst ZIP Codes for Lead in Water in New Hampshire —...

Last updated: June 4, 2026

103 ZIP codes ranked by Lead (mg/L) #1: ZIP 03285 (Thornton, NH) — 566.0 ppb
Lead Violations Lowest Score Safest Flood Risk Energy Cost Radon PFAS Reliability EJ Index Homebuyer Risk CO & Gas Safest Gas Remediation Burden Unresolved Violations (by Utility) Water Equity (by Utility)

Out of 103 ZIP codes with data in New Hampshire, these are the highest-ranked areas for lead (mg/l). See also: National Worst ZIP Codes for Lead in Water | All New Hampshire Rankings

Statistic Value
ZIP codes ranked 103
Highest value 566.0 ppb
Median value 2.0 ppb
State New Hampshire

Top 100 Worst ZIP Codes

Rank ZIP Code City State Lead (mg/L) Safety Score
1 03285 Thornton NH 566.0 ppb 53/100
2 03221 Bradford NH 381.0 ppb 53/100
3 03809 Alton NH 210.0 ppb 55/100
4 03461 Rindge NH 126.0 ppb 58/100
5 03048 Greenville NH 110.0 ppb 55/100
6 03047 Greenfield NH 66.0 ppb 53/100
7 03447 Fitzwilliam NH 53.0 ppb 58/100
8 03869 Rollinsford NH 43.0 ppb 40/100
9 03057 Mont Vernon NH 40.0 ppb 50/100
10 03223 Campton NH 37.0 ppb 52/100
11 03816 Center Tuftonboro NH 37.0 ppb 31/100
12 03254 Moultonborough NH 36.0 ppb 41/100
13 03768 Lyme NH 36.0 ppb 58/100
14 03245 Holderness NH 32.0 ppb 47/100
15 03467 Westmoreland NH 32.0 ppb 58/100
16 03848 Kingston NH 26.0 ppb 56/100
17 03849 Madison NH 25.0 ppb 12/100
18 03238 Glencliff NH 24.0 ppb 49/100
19 03242 Henniker NH 23.0 ppb 54/100
20 03256 New Hampton NH 23.0 ppb 33/100
21 03838 Glen NH 23.0 ppb 15/100
22 03255 Newbury NH 22.0 ppb 57/100
23 03266 Rumney NH 21.0 ppb 49/100
24 03580 Franconia NH 19.0 ppb 56/100
25 03603 Charlestown NH 19.0 ppb 58/100
26 03814 Center Ossipee NH 19.0 ppb 34/100
27 03864 Ossipee NH 19.0 ppb 38/100
28 03886 Tamworth NH 18.0 ppb 43/100
29 03220 Belmont NH 16.0 ppb 53/100
30 03258 Chichester NH 16.0 ppb 58/100
31 03741 Canaan NH 16.0 ppb 52/100
32 03813 Center Conway NH 16.0 ppb 45/100
33 03431 Keene NH 15.0 ppb 73/100
34 03435 Keene NH 15.0 ppb 83/100
35 03445 Sullivan NH 15.0 ppb 53/100
36 03448 Gilsum NH 15.0 ppb 63/100
37 03773 Newport NH 14.0 ppb 54/100
38 03458 Peterborough NH 9.0 ppb 67/100
39 03561 Littleton NH 8.0 ppb 75/100
40 03222 Bristol NH 7.0 ppb 73/100
41 03251 Lincoln NH 7.0 ppb 78/100
42 03753 Grantham NH 7.0 ppb 76/100
43 03253 Meredith NH 6.0 ppb 78/100
44 03824 Durham NH 5.0 ppb 78/100
45 03053 Londonderry NH 4.0 ppb 76/100
46 03246 Laconia NH 4.0 ppb 78/100
47 03247 Laconia NH 4.0 ppb 83/100
48 03235 Franklin NH 3.0 ppb 83/100
49 03874 Seabrook NH 3.0 ppb 70/100
50 03055 Milford NH 2.0 ppb 82/100
51 03060 Nashua NH 2.0 ppb 78/100
52 03061 Nashua NH 2.0 ppb 83/100
53 03062 Nashua NH 2.0 ppb 78/100
54 03063 Nashua NH 2.0 ppb 83/100
55 03064 Nashua NH 2.0 ppb 83/100
56 03079 Salem NH 2.0 ppb 69/100
57 03264 Plymouth NH 2.0 ppb 77/100
58 03570 Berlin NH 2.0 ppb 83/100
59 03743 Claremont NH 2.0 ppb 77/100
60 03755 Hanover NH 2.0 ppb 83/100
61 03756 Lebanon NH 2.0 ppb 78/100
62 03766 Lebanon NH 2.0 ppb 74/100
63 03811 Atkinson NH 2.0 ppb 66/100
64 03833 Exeter NH 2.0 ppb 72/100
65 03839 Rochester NH 2.0 ppb 81/100
66 03841 Hampstead NH 2.0 ppb 83/100
67 03857 Newmarket NH 2.0 ppb 78/100
68 03866 Rochester NH 2.0 ppb 81/100
69 03867 Rochester NH 2.0 ppb 76/100
70 03868 Rochester NH 2.0 ppb 81/100
71 03894 Wolfeboro NH 2.0 ppb 69/100
72 03052 Litchfield NH 1.0 ppb 83/100
73 03054 Merrimack NH 1.0 ppb 72/100
74 03077 Raymond NH 1.0 ppb 70/100
75 03101 Manchester NH 1.0 ppb 80/100
76 03102 Manchester NH 1.0 ppb 75/100
77 03103 Manchester NH 1.0 ppb 75/100
78 03104 Manchester NH 1.0 ppb 75/100
79 03105 Manchester NH 1.0 ppb 79/100
80 03106 Hooksett NH 1.0 ppb 78/100
81 03107 Manchester NH 1.0 ppb 79/100
82 03108 Manchester NH 1.0 ppb 79/100
83 03109 Manchester NH 1.0 ppb 80/100
84 03111 Manchester NH 1.0 ppb 79/100
85 03301 Concord NH 1.0 ppb 53/100
86 03302 Concord NH 1.0 ppb 58/100
87 03303 Concord NH 1.0 ppb 53/100
88 03305 Concord NH 1.0 ppb 50/100
89 03771 Monroe NH 1.0 ppb 78/100
90 03801 Portsmouth NH 1.0 ppb 77/100
91 03802 Portsmouth NH 1.0 ppb 82/100
92 03803 Portsmouth NH 1.0 ppb 82/100
93 03804 Portsmouth NH 1.0 ppb 82/100
94 03812 Bartlett NH 1.0 ppb 60/100
95 03818 Conway NH 1.0 ppb 59/100
96 03820 Dover NH 1.0 ppb 78/100
97 03821 Dover NH 1.0 ppb 83/100
98 03822 Dover NH 1.0 ppb 83/100
99 03823 Madbury NH 1.0 ppb 46/100
100 03842 Hampton NH 1.0 ppb 67/100

Methodology

Lead rankings are based on the 90th percentile lead testing value (PB90) reported by water systems under the Lead and Copper Rule. When CCR data is unavailable, EPA SDWIS lead sampling data is used. The EPA action level for lead is 15 ppb (0.015 mg/L). There is no safe level of lead exposure.

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 is a dangerous lead level in water?

The EPA action level is 15 parts per billion (ppb). The American Academy of Pediatrics recommends no more than 1 ppb for school drinking water. There is no safe level of lead exposure for children.

How is lead measured in water?

Water systems collect samples from homes with known lead service lines or lead solder. The 90th percentile value (PB90) means 90% of samples tested below that level. If PB90 exceeds 15 ppb, the system must take corrective action.

Explore More Rankings

How this ranking is calculated, data sources, and limitations: Rankings Methodology →

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Disclaimer: Rankings are based on EPA, FEMA, and federal agency data. They reflect historical patterns and risk indicators, not necessarily current conditions. For the most current information, contact your local water utility or request a Consumer Confidence Report.

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