Tap water in O Fallon, MO — ZIP 63376
2 public water systems serving about 85,090 people. PFAS "forever chemicals" have been detected here.
C
Fair
PFAS detected: at least one system serving this ZIP reported PFAS in EPA UCMR 5
testing. Levels and the 2024 federal limits are shown per system below.
Water systems serving 63376
St Peters Pws
PWSID MO6010719 · serves 52,575 ·
surface water
0 health-based / 0 total violations (5 yrs)
· PFAS up to 10.6 ppt — above federal limit
Ofallon Pws
PWSID MO6010588 · serves 32,515 ·
surface water
0 health-based / 1 total violations (5 yrs)
· PFAS up to 6.1 ppt
Grades summarize EPA SDWIS violation records (last 5 years) and UCMR 5 PFAS results. They are informational, not a health determination. Methodology