2026 Rankings

EPA Radon Zone 1 ZIP Codes in Connecticut - 2026

Last updated: August 31, 2026

216 ZIP codes ranked by Radon Zone #1: ZIP 06482 (Sandy Hook, CT) - Zone 1 (highest potential)
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 216 ZIP codes with data in Connecticut, these are the lowest-ranked areas for radon zone. See also: National ZIP Codes in EPA Radon Zone 1 | All Connecticut Rankings

Statistic Value
ZIP codes ranked 216
Lowest value Zone 1 (highest potential)
Median value Zone 1 (highest potential)
State Connecticut

100 Lowest-Ranked ZIP Codes

Rank ZIP Code City State Radon Zone Safety Score
1 06482 Sandy Hook CT Zone 1 (highest potential) 33/100
2 06488 Southbury CT Zone 1 (highest potential) 33/100
3 06804 Brookfield CT Zone 1 (highest potential) 33/100
4 06810 Danbury CT Zone 1 (highest potential) 33/100
5 06811 Danbury CT Zone 1 (highest potential) 33/100
6 06333 East Lyme CT Zone 1 (highest potential) 36/100
7 06357 Niantic CT Zone 1 (highest potential) 36/100
8 06801 Bethel CT Zone 1 (highest potential) 36/100
9 06410 Cheshire CT Zone 1 (highest potential) 37/100
10 06416 Cromwell CT Zone 1 (highest potential) 37/100
11 06382 Uncasville CT Zone 1 (highest potential) 41/100
12 06415 Colchester CT Zone 1 (highest potential) 41/100
13 06450 Meriden CT Zone 1 (highest potential) 41/100
14 06492 Wallingford CT Zone 1 (highest potential) 41/100
15 06877 Ridgefield CT Zone 1 (highest potential) 42/100
16 06473 North Haven CT Zone 1 (highest potential) 43/100
17 06470 Newtown CT Zone 1 (highest potential) 44/100
18 06455 Middlefield CT Zone 1 (highest potential) 45/100
19 06351 Jewett City CT Zone 1 (highest potential) 46/100
20 06457 Middletown CT Zone 1 (highest potential) 46/100
21 06716 Wolcott CT Zone 1 (highest potential) 46/100
22 06338 Mashantucket CT Zone 1 (highest potential) 47/100
23 06365 Preston CT Zone 1 (highest potential) 47/100
24 06611 Trumbull CT Zone 1 (highest potential) 48/100
25 06762 Middlebury CT Zone 1 (highest potential) 48/100
26 06451 Meriden CT Zone 1 (highest potential) 49/100
27 06850 Norwalk CT Zone 1 (highest potential) 49/100
28 06851 Norwalk CT Zone 1 (highest potential) 49/100
29 06855 Norwalk CT Zone 1 (highest potential) 49/100
30 06883 Weston CT Zone 1 (highest potential) 49/100
31 06897 Wilton CT Zone 1 (highest potential) 49/100
32 06360 Norwich CT Zone 1 (highest potential) 50/100
33 06379 Pawcatuck CT Zone 1 (highest potential) 50/100
34 06401 Ansonia CT Zone 1 (highest potential) 50/100
35 06403 Beacon Falls CT Zone 1 (highest potential) 50/100
36 06405 Branford CT Zone 1 (highest potential) 50/100
37 06413 Clinton CT Zone 1 (highest potential) 50/100
38 06418 Derby CT Zone 1 (highest potential) 50/100
39 06437 Guilford CT Zone 1 (highest potential) 50/100
40 06443 Madison CT Zone 1 (highest potential) 50/100
41 06468 Monroe CT Zone 1 (highest potential) 50/100
42 06471 North Branford CT Zone 1 (highest potential) 50/100
43 06472 Northford CT Zone 1 (highest potential) 50/100
44 06475 Old Saybrook CT Zone 1 (highest potential) 50/100
45 06477 Orange CT Zone 1 (highest potential) 50/100
46 06478 Oxford CT Zone 1 (highest potential) 50/100
47 06483 Seymour CT Zone 1 (highest potential) 50/100
48 06484 Shelton CT Zone 1 (highest potential) 50/100
49 06498 Westbrook CT Zone 1 (highest potential) 50/100
50 06510 New Haven CT Zone 1 (highest potential) 50/100
51 06511 New Haven CT Zone 1 (highest potential) 50/100
52 06512 East Haven CT Zone 1 (highest potential) 50/100
53 06513 New Haven CT Zone 1 (highest potential) 50/100
54 06514 Hamden CT Zone 1 (highest potential) 50/100
55 06515 New Haven CT Zone 1 (highest potential) 50/100
56 06516 West Haven CT Zone 1 (highest potential) 50/100
57 06517 Hamden CT Zone 1 (highest potential) 50/100
58 06518 Hamden CT Zone 1 (highest potential) 50/100
59 06519 New Haven CT Zone 1 (highest potential) 50/100
60 06525 Woodbridge CT Zone 1 (highest potential) 50/100
61 06604 Bridgeport CT Zone 1 (highest potential) 50/100
62 06605 Bridgeport CT Zone 1 (highest potential) 50/100
63 06606 Bridgeport CT Zone 1 (highest potential) 50/100
64 06607 Bridgeport CT Zone 1 (highest potential) 50/100
65 06608 Bridgeport CT Zone 1 (highest potential) 50/100
66 06610 Bridgeport CT Zone 1 (highest potential) 50/100
67 06612 Easton CT Zone 1 (highest potential) 50/100
68 06614 Stratford CT Zone 1 (highest potential) 50/100
69 06615 Stratford CT Zone 1 (highest potential) 50/100
70 06807 Cos Cob CT Zone 1 (highest potential) 50/100
71 06820 Darien CT Zone 1 (highest potential) 50/100
72 06824 Fairfield CT Zone 1 (highest potential) 50/100
73 06825 Fairfield CT Zone 1 (highest potential) 50/100
74 06830 Greenwich CT Zone 1 (highest potential) 50/100
75 06831 Greenwich CT Zone 1 (highest potential) 50/100
76 06870 Old Greenwich CT Zone 1 (highest potential) 50/100
77 06878 Riverside CT Zone 1 (highest potential) 50/100
78 06890 Southport CT Zone 1 (highest potential) 50/100
79 06901 Stamford CT Zone 1 (highest potential) 50/100
80 06903 Stamford CT Zone 1 (highest potential) 50/100
81 06905 Stamford CT Zone 1 (highest potential) 50/100
82 06906 Stamford CT Zone 1 (highest potential) 50/100
83 06907 Stamford CT Zone 1 (highest potential) 50/100
84 06340 Groton CT Zone 1 (highest potential) 55/100
85 06442 Ivoryton CT Zone 1 (highest potential) 60/100
86 06704 Waterbury CT Zone 1 (highest potential) 63/100
87 06708 Waterbury CT Zone 1 (highest potential) 63/100
88 06320 New London CT Zone 1 (highest potential) 64/100
89 06355 Mystic CT Zone 1 (highest potential) 64/100
90 06385 Waterford CT Zone 1 (highest potential) 64/100
91 06712 Prospect CT Zone 1 (highest potential) 64/100
92 06702 Waterbury CT Zone 1 (highest potential) 65/100
93 06705 Waterbury CT Zone 1 (highest potential) 65/100
94 06706 Waterbury CT Zone 1 (highest potential) 65/100
95 06770 Naugatuck CT Zone 1 (highest potential) 65/100
96 06378 Stonington CT Zone 1 (highest potential) 66/100
97 06480 Portland CT Zone 1 (highest potential) 66/100
98 06853 Norwalk CT Zone 1 (highest potential) 66/100
99 06854 Norwalk CT Zone 1 (highest potential) 66/100
100 06409 Centerbrook CT Zone 1 (highest potential) 67/100

Methodology

This ranking is limited to EPA county-level radon zone classification. Zone 1 identifies the highest county-level potential category; it does not measure a home or establish whether any building is above an action level. Within Zone 1, ZIP codes are sub-ranked by Home Safety Score to organize area context.

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 is EPA Radon Zone 1?

Zone 1 is the EPA highest county-level radon-potential category. It is not a measurement for a home and cannot determine whether a building is above an action level. A home test is required for that decision.

Should I test for radon?

The EPA recommends testing all homes regardless of radon zone. A DIY test kit costs $15-40. Professional testing costs $150-250. If levels exceed 4 pCi/L, mitigation systems ($800-2,500) can reduce radon by up to 99%.

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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