2026 Rankings

Worst CO & Gas Risk ZIP Codes in Connecticut — 2026

Last updated: June 4, 2026

282 ZIP codes ranked by Gas Risk Score #1: ZIP 06075 (Stafford, CT) — 6/100
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 282 ZIP codes with data in Connecticut, these are the highest-ranked areas for gas risk score. See also: National ZIP Codes with Worst CO & Gas Safety Risk | All Connecticut Rankings

Statistic Value
ZIP codes ranked 282
Highest value 6/100
Median value 1/100
State Connecticut

Top 100 Worst ZIP Codes

Rank ZIP Code City State Gas Risk Score Safety Score
1 06075 Stafford CT 6/100 66/100
2 06401 Ansonia CT 6/100 53/100
3 06403 Beacon Falls CT 6/100 53/100
4 06405 Branford CT 6/100 55/100
5 06408 Cheshire CT 6/100 50/100
6 06410 Cheshire CT 6/100 48/100
7 06411 Cheshire CT 6/100 50/100
8 06418 Derby CT 6/100 45/100
9 06437 Guilford CT 6/100 55/100
10 06443 Madison CT 6/100 55/100
11 06450 Meriden CT 6/100 56/100
12 06451 Meriden CT 6/100 56/100
13 06454 Meriden CT 6/100 61/100
14 06460 Milford CT 6/100 40/100
15 06461 Milford CT 6/100 50/100
16 06471 North Branford CT 6/100 55/100
17 06472 Northford CT 6/100 45/100
18 06473 North Haven CT 6/100 40/100
19 06477 Orange CT 6/100 42/100
20 06478 Oxford CT 6/100 60/100
21 06483 Seymour CT 6/100 65/100
22 06487 South Britain CT 6/100 40/100
23 06488 Southbury CT 6/100 51/100
24 06490 New Haven County CT 6/100 —
25 06492 Wallingford CT 6/100 55/100
26 06493 Wallingford CT 6/100 60/100
27 06494 Wallingford CT 6/100 60/100
28 06495 Wallingford CT 6/100 60/100
29 06501 New Haven CT 6/100 70/100
30 06502 New Haven CT 6/100 66/100
31 06503 New Haven CT 6/100 70/100
32 06504 New Haven CT 6/100 66/100
33 06505 New Haven CT 6/100 70/100
34 06506 New Haven CT 6/100 70/100
35 06507 New Haven CT 6/100 70/100
36 06508 New Haven CT 6/100 66/100
37 06509 New Haven CT 6/100 66/100
38 06510 New Haven CT 6/100 70/100
39 06511 New Haven CT 6/100 65/100
40 06512 East Haven CT 6/100 30/100
41 06513 New Haven CT 6/100 60/100
42 06514 Hamden CT 6/100 40/100
43 06515 New Haven CT 6/100 60/100
44 06516 West Haven CT 6/100 51/100
45 06517 Hamden CT 6/100 45/100
46 06518 Hamden CT 6/100 35/100
47 06519 New Haven CT 6/100 65/100
48 06520 New Haven CT 6/100 66/100
49 06521 New Haven CT 6/100 66/100
50 06524 Bethany CT 6/100 53/100
51 06525 Woodbridge CT 6/100 40/100
52 06530 New Haven CT 6/100 66/100
53 06531 New Haven CT 6/100 70/100
54 06532 New Haven CT 6/100 66/100
55 06533 New Haven CT 6/100 66/100
56 06534 New Haven CT 6/100 66/100
57 06535 New Haven CT 6/100 66/100
58 06536 New Haven CT 6/100 66/100
59 06537 New Haven CT 6/100 66/100
60 06538 New Haven CT 6/100 66/100
61 06540 New Haven CT 6/100 70/100
62 06643 New Haven County CT 6/100 —
63 06701 Waterbury CT 6/100 65/100
64 06702 Waterbury CT 6/100 65/100
65 06703 Waterbury CT 6/100 60/100
66 06704 Waterbury CT 6/100 60/100
67 06705 Waterbury CT 6/100 60/100
68 06706 Waterbury CT 6/100 65/100
69 06708 Waterbury CT 6/100 60/100
70 06710 Waterbury CT 6/100 65/100
71 06712 Prospect CT 6/100 66/100
72 06716 Wolcott CT 6/100 61/100
73 06720 Waterbury CT 6/100 60/100
74 06721 Waterbury CT 6/100 65/100
75 06722 Waterbury CT 6/100 60/100
76 06723 Waterbury CT 6/100 60/100
77 06724 Waterbury CT 6/100 60/100
78 06725 Waterbury CT 6/100 60/100
79 06726 Waterbury CT 6/100 60/100
80 06749 Waterbury CT 6/100 60/100
81 06762 Middlebury CT 6/100 65/100
82 06770 Naugatuck CT 6/100 65/100
83 06001 Avon CT 1/100 78/100
84 06002 Bloomfield CT 1/100 69/100
85 06006 Windsor CT 1/100 66/100
86 06010 Bristol CT 1/100 67/100
87 06011 Bristol CT 1/100 83/100
88 06013 Burlington CT 1/100 95/100
89 06016 Broad Brook CT 1/100 87/100
90 06019 Canton CT 1/100 88/100
91 06020 Canton Center CT 1/100 73/100
92 06022 Collinsville CT 1/100 66/100
93 06023 East Berlin CT 1/100 73/100
94 06025 East Glastonbury CT 1/100 53/100
95 06026 East Granby CT 1/100 83/100
96 06027 East Hartland CT 1/100 53/100
97 06028 East Windsor Hill CT 1/100 66/100
98 06030 Farmington CT 1/100 91/100
99 06032 Farmington CT 1/100 81/100
100 06033 Glastonbury CT 1/100 81/100

Methodology

Gas risk rankings use PHMSA gas distribution incident data (2004-2026), mapped to counties and ZIP codes. Risk scores (0-100) factor in total incidents, fatalities, and recency. Counties with more incidents, deaths, and recent events score highest. Data source: U.S. DOT Pipeline and Hazardous Materials Safety Administration.

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 gas distribution incident?

Gas distribution incidents involve failures in the local natural gas pipeline network — the pipes that carry gas from main lines to homes and businesses. These can cause explosions, fires, carbon monoxide poisoning, and property damage. PHMSA tracks all reported incidents nationally.

How can I protect my home from CO and gas leaks?

Install CO detectors on every level of your home (CPSC recommendation). Have gas appliances inspected annually by a licensed technician. Know the signs of a gas leak: rotten egg smell, hissing near gas lines, dead vegetation near pipelines. If you smell gas, leave immediately and call 911.

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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