PFAS · Missouri
PFAS in Missouri drinking water: EPA’s final survey results
EPA’s national PFAS survey (UCMR 5) tested 227 of the community water systems that serve homes in Missouri. 73 found at least one of 29 PFAS above the laboratory reporting level, and 6 had a PFOA or PFOS sampling-location yearly average at or above EPA’s 4.0 ppt limit. Samples were collected from January 2023 to January 2026.
Data as of EPA UCMR 5 final release, August 2026 (file dated Aug 28, 2026) · EPA SDWIS 2026Q2 (file dated Jul 9, 2026). How we build these pages
PFBA was the compound Missouri community systems found most often: 53 of 227 tested systems measured it above the reporting level. Across the country, 35% of surveyed community systems found at least one PFAS; in Missouri the share is 32%. The largest Missouri system with a detection, Mo American St Louis St Charles Counties, serves 1,111,000 people and found 1 of the 29 compounds.
Which PFAS were found most often in Missouri
Each row counts the Missouri community water systems where that compound was measured above the reporting level at least once. A detection is a measurement, not a violation: most of these compounds have no federal limit.
| Compound | Systems where found | Systems tested | Share |
|---|---|---|---|
| PFBA | 53 | 227 | 23% |
| PFPeA | 10 | 227 | 4% |
| PFHxS | 9 | 227 | 4% |
| PFBS | 8 | 227 | 4% |
| PFHxA | 5 | 227 | 2% |
| PFOS | 5 | 227 | 2% |
| PFOA | 4 | 227 | 2% |
| PFHpA | 1 | 227 | 0% |
| PFPeS | 1 | 227 | 0% |
Missouri systems with the most PFAS found
The 10 surveyed community water systems that found the most different PFAS, with PFOA and PFOS compared to EPA’s 4.0 ppt limits on the yearly average at the highest sampling location. Larger systems come first when counts tie.
| Water system | People served | PFAS found (of 29) | PFOA | PFOS |
|---|---|---|---|---|
| St James PWS MO3010712 | 3,935 | 7 | — not detected above the reporting level | 5.0 ppt at or above the MCL |
| St Peters PWS MO6010719 | 52,575 | 4 | 4.8 ppt at or above the MCL | — not detected above the reporting level |
| Ralls County Pwsd 1 MO2024499 | 7,662 | 4 | 5.3 ppt at or above the MCL | — not detected above the reporting level |
| North Kansas City PWS MO1010580 | 4,500 | 3 | — not detected above the reporting level | — not detected above the reporting level |
| City Utilities of Springfield MO5010754 | 210,898 | 2 | — not detected above the reporting level | 1.1 ppt below the MCL |
| Ofallon PWS MO6010588 | 32,515 | 2 | — not detected above the reporting level | — not detected above the reporting level |
| Farmington PWS MO4010270 | 18,217 | 2 | — not detected above the reporting level | — not detected above the reporting level |
| Sikeston PWS MO4010743 | 16,291 | 2 | — not detected above the reporting level | — not detected above the reporting level |
| Platte Co Pwsd 4 MO1024478 | 9,552 | 2 | — not detected above the reporting level | — not detected above the reporting level |
| Boonville PWS MO3010089 | 7,964 | 2 | — not detected above the reporting level | — not detected above the reporting level |
Counties with the most systems that found PFAS
- Clay County 6 of 11 surveyed systems
- Cass County 6 of 9 surveyed systems
- St. Charles County 4 of 6 surveyed systems
- Platte County 4 of 5 surveyed systems
- Jefferson County 4 of 14 surveyed systems
- Jackson County 3 of 13 surveyed systems
- Clinton County 3 of 4 surveyed systems
- Pike County 3 of 3 surveyed systems