73.9
County avg score
4
Cities ranked
75%
A or B grade
25%
D or F grade
2
Health violations
4
PFAS detected
Grade Distribution
How St. Charles cities scored
A
1
25%
Excellent
B
2
50%
Good
C
0
0%
Fair
D
0
0%
Poor
F
1
25%
Failing
Comparison
County vs Missouri average
▼ 5.2 pts below state average
City Map
Water quality across St. Charles
Each dot is a city, colored by grade. Click any city to view its full report.
Highlights
Top & bottom cities in St. Charles
Best cities
Worst cities
County context
88.7%
of residents on fluoridated water (CDC, 2020)
Full Rankings
All 4 cities in St. Charles
| # | City | Grade | Score | Score | Population | Violations | Issues |
|---|---|---|---|---|---|---|---|
| 1 | Wentzville | A- | 88.1 | 42K | 37 | Health Unresolved | |
| 2 | St. Charles | B+ | 83.5 | 73K | 5 | Unresolved | |
| 3 | St. Peters | B+ | 80.5 | 53K | 2 | PFAS Unresolved | |
| 4 | O Fallon | F | 43.4 | 138K | 86 | Health Unresolved |