Jefferson County tap water
0 of 14 water systems serving Jefferson County with full PFAS testing averaged above a 2024 federal PFAS level at one or more sampling points.
- 68 community water systems list this county as served; 14 serve 3,300+ people with full PFAS testing.
- 9 had a health-based violation since 2021-10-26.
Largest systems serving this county
| System | Source | People served (whole system) | PFAS above a 2024 level? | Violations since 2021-10-26 |
|---|---|---|---|---|
| Jefferson CO Cons Pwsd C 1 | Purchased surface water | 37,000 | No | 0 |
| Jefferson County Pwsd 1 | Purchased surface water | 21,113 | No | 0 |
| Jefferson County Pwsd 3 | Purchased surface water | 17,000 | No | 0 |
| Jefferson County Pwsd 2 | Surface water | 16,548 | No | 0 |
| Festus PWS | Purchased groundwater (surface influence) | 13,000 | No | 0 |
| Jefferson County Pwsd 10 | Purchased surface water | 10,000 | No | 0 |
| Jefferson County Pwsd 5 | Groundwater | 8,000 | No | 0 |
| Jefferson County Pwsd 6 | Groundwater | 7,500 | No | 0 |
| Desoto PWS | Groundwater | 6,400 | No | 0 |
| Jefferson County Pwsd 7 | Groundwater | 6,100 | No | 0 |
| Pevely PWS | Groundwater | 5,600 | No | 0 |
| Herculaneum PWS | Purchased groundwater (surface influence) | 5,000 | No | 0 |
Which one is yours? A county usually has several utilities. Your bill or your utility's annual water-quality report names yours. Population is for the whole system, which can cross county lines.
Not medical or legal advice. UCMR 5 results are screening data, not compliance determinations.
Sources and freshness
Public-water-system facts, violations and lead/copper results: EPA ECHO SDWA download (SDWIS snapshot 2026-10-13). PFAS and lithium results: EPA UCMR 5 final data (sampling 2023–2025). Both are U.S. government works, downloaded 2026-10-26. Numbers are computed by the published method; the same fields are in the open data files.