COUNTY WATER-SYSTEM LEDGER
St. Clair, Illinois
EPA’s September 2026 export lists 11 active community water systems serving St. Clair, Illinois, with 1 current-violation flags and 0 serious-violator flags among the covered systems.
Source: EPA SDWIS system-search export · Active community systems serving 2,500+ people · Snapshot 13 Sep 2026
01 / SYSTEMS
Water systems serving St. Clair, Illinois
EPA associates 11 covered systems with St. Clair, Illinois; their reported population-served values total 242,392 and may overlap.
Ordered by reported population served. Open any record for separate health, monitoring, notice, other, and serious-violator flags.
| Water system | Population served | Primary source | Current export status |
|---|---|---|---|
| Il American-East St LouisIL1635040 | 131,368 | Surface water | No current violation flagged |
| O FallonIL1631100 | 46,603 | Surface water purchased | No current violation flagged |
| CaseyvilleIL1630250 | 13,798 | Surface water purchased | No current violation flagged |
| Cahokia HeightsIL1635000 | 12,528 | Surface water purchased | No current violation flagged |
| MascoutahIL1630800 | 8,759 | Surface water purchased | Other current violation flag |
| American Water Oper And Maintenance, LlcIL1635237 | 6,779 | Surface water purchased | No current violation flagged |
| LebanonIL1630650 | 4,714 | Surface water purchased | No current violation flagged |
| FreeburgIL1630600 | 4,707 | Surface water purchased | No current violation flagged |
| DupoIL1630350 | 4,684 | Ground water | No current violation flagged |
| SmithtonIL1631300 | 4,381 | Surface water purchased | No current violation flagged |
| MillstadtIL1630850 | 4,071 | Surface water purchased | No current violation flagged |
02 / SOURCE MIX
Primary water sources for St. Clair, Illinois
EPA classifies 11 systems serving St. Clair, Illinois across 3 primary-source categories; Surface water is the largest category with 1 systems.
It is the sum of each listed system's reported population served, not a census estimate. Service areas can overlap and some systems list multiple cities or counties.