Missouri
St. Charles County drinking water quality
55 active public water systems serve 1,427,837 people in St. Charles County. 21 are compliant, 34 had at least one EPA violation in the past three years, 0 are designated serious violators, and 1 carries a health flag.
Needs attention
Community water systems
19 systems, largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
MO American ST Louis ST Charles Counties |
1,111,000 | 0 | 0 | |
|
ST Charles County Pwsd 2 |
100,587 | 1 | 0 | |
|
ST Charles PWS St. Charles |
78,961 | 1 | 0 | |
|
ST Peters PWS St. Peters |
52,575 | 0 | 0 | |
|
Wentzville PWS Wentzville |
41,784 | 1 | 1 | |
|
Ofallon PWS O Fallon |
32,515 | 1 | 0 | |
|
ST Paul PWS |
1,700 | 1 | 0 | |
|
ST Charles CO Pwsd 2 Augusta |
881 | 0 | 0 | |
|
ST Charles Pwsd 2 Foristell Foristell |
550 | 1 | 1 | |
|
MO American Jaxson Foristell |
535 | 0 | 0 | |
|
Ecm Water & Sewer Authority Flint Hill Flint Hill |
469 | 0 | 0 | |
|
Portage Des Sioux PWS Portagedessioux |
345 | 1 | 1 | |
|
Prairie View Acres Subd |
135 | 2 | 1 | |
|
ST Charles CO Pwsd 2 Sumac Ridge |
103 | 1 | 0 | |
|
Tara Oaks Manor Assn |
100 | 1 | 1 | |
|
Weldon Spring Heights Village PWS Weldon Spr Hght |
100 | 0 | 0 | |
|
Big Country Acres Subdivision |
90 | 3 | 2 | |
|
Confluence Rivers Stone Ridge Meadows |
60 | 1 | 0 | |
|
Country Estates |
50 | 2 | 2 |
Non-community systems (36: schools, campgrounds, workplaces, restaurants)
These systems serve places people visit rather than homes.
Inactive systems (62, 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 Missouri 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.