Tap water in Williamstown, MO — ZIP 63117
3 public water systems serving about 1,423,709 people. PFAS "forever chemicals" have been detected here.
B
Good
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 63117
Mo American St Louis St Charles Counties
PWSID MO6010716 · serves 1,111,000 ·
surface water
0 health-based / 0 total violations (5 yrs)
· PFAS up to 5.1 ppt
St Louis City Pws
PWSID MO6010715 · serves 304,709 ·
surface water
0 health-based / 8 total violations (5 yrs)
Clark County Cons Pwsd 1
PWSID MO2024138 · serves 8,000 ·
groundwater
0 health-based / 2 total violations (5 yrs)
Grades summarize EPA SDWIS violation records (last 5 years) and UCMR 5 PFAS results. They are informational, not a health determination. Methodology