2026 Rankings

ZIP Codes with Most EPA Violations in Illinois — 2026

Last updated: June 4, 2026

1,089 ZIP codes ranked by Violations #1: ZIP 62450 (Olney, IL) — 114
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 1,089 ZIP codes with data in Illinois, these are the highest-ranked areas for violations. See also: National ZIP Codes with Most EPA Water Violations | All Illinois Rankings

Statistic Value
ZIP codes ranked 1,089
Highest value 114
Median value 4
State Illinois

Top 100 Worst ZIP Codes

Rank ZIP Code City State Violations Safety Score
1 62450 Olney IL 114 82/100
2 60150 Malta IL 92 50/100
3 61350 Ottawa IL 73 66/100
4 60431 Joliet IL 51 49/100
5 60432 Joliet IL 51 44/100
6 60433 Joliet IL 51 44/100
7 60434 Joliet IL 51 59/100
8 60435 Joliet IL 51 49/100
9 60436 Joliet IL 51 49/100
10 61282 Silvis IL 36 47/100
11 62216 Aviston IL 36 35/100
12 61701 Bloomington IL 31 57/100
13 61702 Bloomington IL 31 62/100
14 61704 Bloomington IL 31 57/100
15 61705 Bloomington IL 31 62/100
16 61709 Bloomington IL 31 55/100
17 61710 Bloomington IL 31 55/100
18 61791 Bloomington IL 31 55/100
19 61799 Bloomington IL 31 55/100
20 62259 Menard IL 30 61/100
21 62812 Benton IL 30 54/100
22 61354 Peru IL 29 57/100
23 62424 Dieterich IL 29 73/100
24 62355 Nebo IL 28 63/100
25 61062 Pearl City IL 24 51/100
26 62414 Beecher City IL 23 53/100
27 62674 Palmyra IL 23 50/100
28 60403 Crest Hill IL 22 72/100
29 61230 Albany IL 22 56/100
30 61771 Secor IL 22 33/100
31 62670 New Berlin IL 21 62/100
32 62886 Sims IL 21 67/100
33 60416 Coal City IL 20 47/100
34 61726 Chenoa IL 20 41/100
35 60290 Chicago IL 19 68/100
36 60472 Robbins IL 19 64/100
37 60481 Wilmington IL 19 54/100
38 60601 Chicago IL 19 71/100
39 60602 Chicago IL 19 71/100
40 60603 Chicago IL 19 71/100
41 60604 Chicago IL 19 71/100
42 60605 Chicago IL 19 68/100
43 60606 Chicago IL 19 71/100
44 60607 Chicago IL 19 71/100
45 60608 Chicago IL 19 71/100
46 60609 Chicago IL 19 66/100
47 60610 Chicago IL 19 66/100
48 60611 Chicago IL 19 71/100
49 60612 Chicago IL 19 71/100
50 60613 Chicago IL 19 71/100
51 60614 Chicago IL 19 66/100
52 60615 Chicago IL 19 71/100
53 60616 Chicago IL 19 71/100
54 60617 Chicago IL 19 66/100
55 60618 Chicago IL 19 66/100
56 60619 Chicago IL 19 61/100
57 60620 Chicago IL 19 66/100
58 60621 Chicago IL 19 71/100
59 60622 Chicago IL 19 71/100
60 60623 Chicago IL 19 71/100
61 60624 Chicago IL 19 66/100
62 60625 Chicago IL 19 61/100
63 60626 Chicago IL 19 66/100
64 60628 Chicago IL 19 61/100
65 60629 Chicago IL 19 66/100
66 60630 Chicago IL 19 66/100
67 60631 Chicago IL 19 66/100
68 60632 Chicago IL 19 71/100
69 60633 Chicago IL 19 66/100
70 60634 Chicago IL 19 66/100
71 60636 Chicago IL 19 66/100
72 60637 Chicago IL 19 61/100
73 60638 Chicago IL 19 71/100
74 60639 Chicago IL 19 66/100
75 60640 Chicago IL 19 71/100
76 60641 Chicago IL 19 66/100
77 60642 Chicago IL 19 71/100
78 60643 Chicago IL 19 66/100
79 60644 Chicago IL 19 66/100
80 60645 Chicago IL 19 71/100
81 60646 Chicago IL 19 66/100
82 60647 Chicago IL 19 66/100
83 60649 Chicago IL 19 71/100
84 60651 Chicago IL 19 66/100
85 60652 Chicago IL 19 66/100
86 60653 Chicago IL 19 71/100
87 60654 Chicago IL 19 71/100
88 60655 Chicago IL 19 71/100
89 60656 Chicago IL 19 71/100
90 60657 Chicago IL 19 66/100
91 60659 Chicago IL 19 66/100
92 60660 Chicago IL 19 66/100
93 60661 Chicago IL 19 68/100
94 60664 Chicago IL 19 68/100
95 60666 Chicago IL 19 68/100
96 60668 Chicago IL 19 68/100
97 60669 Chicago IL 19 68/100
98 60670 Chicago IL 19 71/100
99 60673 Chicago IL 19 68/100
100 60674 Chicago IL 19 68/100

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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