Missouri · population 95,355
Lead pipes in O'Fallon, MO
4,452 lines still unidentified
Most of O'Fallon (population 95,355) gets its water from St Charles County PWSD 2. It reported no confirmed lead service lines, but 4,452 of 42,007 lines are still listed as unknown material, so lead hasn't been ruled out.
0% of St Charles County PWSD 2's service lines are lead or galvanized requiring replacement, lower than the Missouri average (3.3%) and lower than the national average (3.1%).
- Lead 0%
- Galvanized (replace) 0%
- Unknown 11%
- Non-lead 89%
Latest lead test for St Charles County PWSD 2 (Jan 2026–Jun 2026): 2.3 ppb at the 90th percentile, against a 15 ppb federal action level. Full test history.
Compliance record: EPA lists no Lead and Copper Rule violations since 2015 for St Charles County PWSD 2.
Water systems serving O'Fallon
| Water system | Lead | Galv. | Unknown | % lead |
|---|---|---|---|---|
| St Charles County PWSD 2Main system | 0 | 0 | 4,452 | 0% |
| Mo American St Louis St Charles CountiesServes nearby areas | 9,422 | 1,247 | 191,341 | 2.7% |
Matched from EPA water system service area boundaries and the cities each system reports serving. Edges of the city may be served by a neighboring system; your water bill names your utility.
Check your address in O'Fallon
The counts above cover the whole water system. To see whether your line is lead, look up your address on St Charles County PWSD 2's official inventory. Utilities had to make these public by October 16, 2024.
No map yet? Do the 2-minute scratch and magnet test.
Protect your drinking water
If your line is lead, galvanized or unknown, use a filter certified to NSF/ANSI 53 for lead for drinking, cooking and baby formula, and use only cold water.
Choosing a lead-certified filter · Testing your water · Replacement cost
Nearby cities
- Dardenne Prairie4,452 unknown
- Lake St. Louis4,452 unknown
- Cottleville10,669 lead + galv. lines
- St. Paulno lead reported
- Weldon Spring10,669 lead + galv. lines
- St. Peters2,860 unknown
- Wentzville4,452 unknown
- St. Charles7 lead + galv. lines
Check another water system
Questions
Does O'Fallon, MO have lead pipes?
None are confirmed, but St Charles County PWSD 2 still lists 4,452 service lines as unknown material.
Who supplies water to O'Fallon?
EPA's service area maps place most of O'Fallon in St Charles County PWSD 2's service area (PWSID MO6024530). Mo American St Louis St Charles Counties also serves parts of the city or nearby areas.
How do I check whether my O'Fallon home has a lead service line?
Search your address on St Charles County PWSD 2's service line inventory map. You can also scratch the pipe where water enters your home: lead is soft, dull gray, scratches to shiny silver and doesn't attract a magnet.
When will lead pipes in O'Fallon be replaced?
EPA's Lead and Copper Rule Improvements require most systems to replace lead and galvanized-requiring-replacement lines by December 31, 2037. Ask St Charles County PWSD 2 whether your street is scheduled and whether it covers the private side.