Illinois
St. Clair County drinking water quality
54 active public water systems serve 255,605 people in St. Clair County. 31 are compliant, 23 had at least one EPA violation in the past three years, 2 are designated serious violators, and 1 carries a health flag.
Needs attention
Community water systems
28 systems, largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
IL American-East ST Louis East St Louis |
131,368 | 0 | 0 | |
|
O Fallon O Fallon |
46,603 | 1 | 0 | |
|
Caseyville Caseyville |
13,798 | 1 | 0 | |
|
Cahokia Heights Cahokia |
12,528 | 0 | 0 | |
|
Mascoutah Mascoutah |
8,759 | 1 | 1 | |
|
American Water Oper and Maintenance, LLC |
6,779 | 0 | 0 | |
|
Lebanon Lebanon |
4,714 | 2 | 0 | |
|
Freeburg Freeburg |
4,707 | 0 | 0 | |
|
Dupo Dupo |
4,684 | 1 | 0 | |
|
Smithton Smithton |
4,381 | 1 | 0 | |
|
Millstadt Millstadt |
4,071 | 0 | 0 | |
|
New Athens New Athens |
1,970 | 1 | 0 | |
|
Marissa Marissa |
1,921 | 2 | 1 | |
|
Prairie Dupont Pwd |
1,863 | 0 | 0 | |
|
Mound Pwd |
1,243 | 4 | 3 | |
|
ST Libory St Libory |
628 | 1 | 0 | |
|
Lenzburg Lenzburg |
616 | 1 | 0 | |
|
Valley View Estates O Fallon |
580 | 2 | 0 | |
|
Southwestern IL Correctional Center East St Louis |
563 | 0 | 0 | |
|
Fayetteville Fayetteville |
490 | 0 | 0 | |
|
Meadowbrook MH Community, LLC Belleville |
463 | 4 | 1 | |
|
S L M Water Commission |
385 | 1 | 0 | |
|
Arapaho Village MHP Belleville |
368 | 0 | 0 | |
|
Summerfield Summerfield |
347 | 0 | 0 | |
|
Fsh Water Commission Smithton |
313 | 2 | 0 | |
|
Ildu Lepere Mhp, LLC Dupo |
250 | 3 | 2 | |
|
Lake Suzanne MHP Shiloh |
108 | 0 | 0 | |
|
Kaskaskia Water District New Athens |
0 | 1 | 0 |
Non-community systems (26: schools, campgrounds, workplaces, restaurants)
These systems serve places people visit rather than homes.
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Karbans Knotty Pines |
200 | 1 | 0 | |
|
ST Clair County Foley Park |
200 | 0 | 0 | |
|
Children of Promise |
50 | 5 | 2 | |
|
ST Michaels Church |
50 | 1 | 0 | |
|
Twice the Ice Freeburg |
50 | 0 | 0 | |
|
New Athens Hanft PK Larry Webe |
30 | 0 | 0 | |
|
Schnucks (138297) |
30 | 0 | 0 | |
|
Schnucks (138313) |
30 | 0 | 0 | |
|
Schnucks (138321) |
30 | 0 | 0 | |
|
Twice the Ice Smithton |
30 | 0 | 0 | |
|
Walmart Supercenter 201 |
30 | 0 | 0 | |
|
BK Ice Cahokia |
25 | 0 | 0 | |
|
Dierbergs |
25 | 0 | 0 | |
|
Freeburg Ice Man |
25 | 0 | 0 | |
|
Fresh Thyme Farmers Market Fairview Hgts |
25 | 0 | 0 | |
|
Millstadt Sportsmans Club |
25 | 1 | 0 | |
|
New Baden Market Center |
25 | 0 | 0 | |
|
Quail Restoration Association |
25 | 0 | 0 | |
|
Scarlett's Cabaret |
25 | 3 | 1 | |
|
Schnucks #148 |
25 | 0 | 0 | |
|
Schnucks 177 O Fallon |
25 | 0 | 0 | |
|
Schnucks 205 Belleville |
25 | 0 | 0 | |
|
Twice the Ice Lebanon |
25 | 0 | 0 | |
|
Twice the Ice Mascoutah |
25 | 0 | 0 | |
|
Twice the Ice ST Libory |
25 | 2 | 0 | |
|
Walmart Supercenter 1418 |
25 | 0 | 0 |
Inactive systems (112, no longer operating or reporting)
Kept for the record and excluded from the county totals above. Browse inactive systems.
About this data
Totals cover active systems. Systems serving more than one county are counted in each county. EPA counts the rules a system was in violation of, not the individual violations; one rule can carry several.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Illinois records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.