Madison County tap water
2 of 19 water systems serving Madison County with full PFAS testing averaged above a 2024 federal PFAS level at one or more sampling points.
- 41 community water systems list this county as served; 16 serve 3,300+ people with full PFAS testing.
- 6 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 |
|---|---|---|---|---|
| IL American-Alton | Surface water | 46,127 | No | 0 |
| IL American-Granite City | Surface water | 33,572 | No | 0 |
| Collinsville | Groundwater | 30,616 | Yes | 0 |
| Edwardsville | Groundwater | 26,808 | No | 0 |
| Troy | Groundwater | 16,962 | No | 0 |
| Bethalto | Groundwater | 15,210 | No | 0 |
| Glen Carbon | Purchased surface water | 12,618 | No | 0 |
| Highland | Surface water | 10,674 | No | 0 |
| Wood River | Groundwater | 10,464 | No | 0 |
| Maryville | Groundwater | 10,150 | No | 0 |
| Fosterburg Pwd | Purchased surface water | 7,940 | No | 0 |
| East Alton | Groundwater | 5,786 | Yes | 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.