2026 Rankings

ZIP Codes with Most EPA Violations in Connecticut — ...

Last updated: June 4, 2026

254 ZIP codes ranked by Violations #1: ZIP 06470 (Newtown, CT) — 62
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 254 ZIP codes with data in Connecticut, these are the highest-ranked areas for violations. See also: National ZIP Codes with Most EPA Water Violations | All Connecticut Rankings

Statistic Value
ZIP codes ranked 254
Highest value 62
Median value 7
State Connecticut

Top 100 Worst ZIP Codes

Rank ZIP Code City State Violations Safety Score
1 06470 Newtown CT 62 57/100
2 06776 New Milford CT 48 67/100
3 06901 Stamford CT 40 69/100
4 06902 Stamford CT 40 54/100
5 06903 Stamford CT 40 59/100
6 06904 Stamford CT 40 69/100
7 06905 Stamford CT 40 59/100
8 06906 Stamford CT 40 64/100
9 06907 Stamford CT 40 64/100
10 06910 Stamford CT 40 65/100
11 06911 Stamford CT 40 65/100
12 06912 Stamford CT 40 65/100
13 06913 Stamford CT 40 65/100
14 06914 Stamford CT 40 65/100
15 06920 Stamford CT 40 65/100
16 06921 Stamford CT 40 65/100
17 06922 Stamford CT 40 65/100
18 06925 Stamford CT 40 65/100
19 06926 Stamford CT 40 65/100
20 06927 Stamford CT 40 65/100
21 06928 Stamford CT 40 65/100
22 06482 Sandy Hook CT 35 51/100
23 06422 Durham CT 34 60/100
24 06801 Bethel CT 33 59/100
25 06234 Brooklyn CT 32 68/100
26 06002 Bloomfield CT 30 69/100
27 06108 East Hartford CT 30 65/100
28 06118 East Hartford CT 30 60/100
29 06128 East Hartford CT 30 66/100
30 06138 East Hartford CT 30 66/100
31 06043 Bolton CT 28 67/100
32 06278 Ashford CT 28 74/100
33 06084 Tolland CT 27 70/100
34 06371 Old Lyme CT 27 40/100
35 06759 Litchfield CT 26 69/100
36 06026 East Granby CT 25 83/100
37 06258 Pomfret CT 25 50/100
38 06415 Colchester CT 25 66/100
39 06424 East Hampton CT 25 61/100
40 06082 Enfield CT 24 81/100
41 06083 Enfield CT 24 94/100
42 06492 Wallingford CT 24 55/100
43 06493 Wallingford CT 24 60/100
44 06494 Wallingford CT 24 60/100
45 06495 Wallingford CT 24 60/100
46 06795 Watertown CT 23 74/100
47 06701 Waterbury CT 22 65/100
48 06702 Waterbury CT 22 65/100
49 06703 Waterbury CT 22 60/100
50 06704 Waterbury CT 22 60/100
51 06705 Waterbury CT 22 60/100
52 06706 Waterbury CT 22 65/100
53 06708 Waterbury CT 22 60/100
54 06710 Waterbury CT 22 65/100
55 06720 Waterbury CT 22 60/100
56 06721 Waterbury CT 22 65/100
57 06722 Waterbury CT 22 60/100
58 06723 Waterbury CT 22 60/100
59 06724 Waterbury CT 22 60/100
60 06725 Waterbury CT 22 60/100
61 06726 Waterbury CT 22 60/100
62 06749 Waterbury CT 22 60/100
63 06471 North Branford CT 21 55/100
64 06357 Niantic CT 20 52/100
65 06420 Salem CT 19 62/100
66 06455 Middlefield CT 19 66/100
67 06484 Shelton CT 19 55/100
68 06340 Groton CT 18 43/100
69 06349 Groton CT 18 54/100
70 06353 Montville CT 18 60/100
71 06524 Bethany CT 18 53/100
72 06281 Woodstock CT 16 46/100
73 06408 Cheshire CT 16 50/100
74 06410 Cheshire CT 16 48/100
75 06411 Cheshire CT 16 50/100
76 06756 Goshen CT 16 69/100
77 06798 Woodbury CT 16 74/100
78 06088 East Windsor CT 15 82/100
79 06241 Dayville CT 15 41/100
80 06279 Willington CT 15 66/100
81 06426 Essex CT 15 52/100
82 06750 Bantam CT 15 76/100
83 06763 Morris CT 15 74/100
84 06069 Sharon CT 14 74/100
85 06074 South Windsor CT 14 78/100
86 06457 Middletown CT 14 56/100
87 06459 Middletown CT 14 61/100
88 06070 Simsbury CT 13 80/100
89 06232 Andover CT 13 74/100
90 06351 Jewett City CT 13 60/100
91 06757 Kent CT 13 74/100
92 06037 Berlin CT 12 81/100
93 06248 Hebron CT 12 78/100
94 06259 Pomfret Center CT 12 78/100
95 06260 Putnam CT 12 71/100
96 06335 Gales Ferry CT 12 56/100
97 06790 Torrington CT 12 72/100
98 06792 Torrington CT 12 76/100
99 06331 Canterbury CT 11 66/100
100 06414 Cobalt CT 11 41/100

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.

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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