Waukesha County tap water
2 of 12 water systems serving Waukesha County with full PFAS testing averaged above a 2024 federal PFAS level at one or more sampling points.
- 73 community water systems list this county as served; 12 serve 3,300+ people with full PFAS testing.
- 18 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 |
|---|---|---|---|---|
| Waukesha Water Utility | Purchased surface water | 70,718 | No | 36 |
| Brookfield Water Utility | Groundwater | 29,070 | No | 0 |
| New Berlin Water Utility | Purchased surface water | 27,899 | No | 0 |
| Menomonee Falls Ww - Surface Water | Purchased surface water | 23,867 | No | 0 |
| Oconomowoc Waterworks | Groundwater | 15,805 | No | 0 |
| Sussex Village Hall & Water Utility | Groundwater | 11,750 | No | 0 |
| Hartland Waterworks | Groundwater | 9,212 | Yes | 0 |
| Pewaukee City Water and Sewer Utility | Groundwater | 8,671 | Yes | 11 |
| Mukwonago Waterworks | Groundwater | 8,190 | No | 0 |
| Pewaukee Village Waterworks | Groundwater | 8,166 | No | 20 |
| Muskego Water Utility | Groundwater | 8,150 | No | 1 |
| Town of Brookfield San Dist 4 | Groundwater | 6,419 | 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.