Groundwater in Waukesha County contains radon, perfluorinated compounds (PFOS, PFOA, PFHXS), and sulfate. Several of these contaminants exceed EPA health standards and warrant attention.
Radon seeps into groundwater from uranium naturally present in the deep rock layers beneath the county. Perfluorinated compounds enter from industrial or consumer product use on the land surface and move down into the water supply. Sulfate dissolves from minerals in the rock as water passes through slowly over time.
Groundwater in Waukesha County is very hard, driven by elevated calcium and magnesium that dissolve from the rock formation below. As water sits in contact with these mineral-rich layers, it picks up dissolved hardness. This character shows up consistently across wells throughout the county.
Wells in Waukesha County commonly exceed EPA health standards for several contaminants. PFOA, PFOS, and PFHXS are synthetic chemicals that accumulate in your body over time and can affect the immune system, thyroid, and liver. Radon is a radioactive gas that enters groundwater from rock layers below and increases lung cancer risk when inhaled from water. Sulfate at elevated levels may cause digestive issues, particularly in infants and people with certain health conditions.
Very hard water is common in county wells and creates practical problems at home. Hard water leaves white, crusty scale buildup on faucets, showerheads, and inside pipes. It reduces how well soap works for cleaning dishes and laundry, and it can shorten the lifespan of water heaters and dishwashers. You may also notice a slightly bitter or mineral taste in the water.
We recommend testing your well with a comprehensive metals and minerals panel, since multiple contaminants exceed health standards in this county. Every well is different, and your well may have higher or lower levels than what is typical here--testing is the only way to know what is actually in your water and how to treat it properly. A comprehensive panel typically costs between $200 and $400. Treatment options like PFAS removal filters and radon mitigation systems can address specific concerns once testing results are in hand.
Not sure if your well is affected? Get certified results in 5–7 days.
Test Your Well Water with Tap Score →| Contaminant | Samples ⓘ | % Above MCL ⓘ | Distribution ⓘ | Confidence ⓘ | Risk ⓘ |
|---|---|---|---|---|---|
| Iron | 284 | 45% | High | High | |
| Manganese | 262 | 18% | High | High | |
| Chloride | 871 | 9% | High | Moderate | |
| Sulfate | 268 | 5% | High | Moderate | |
| PFOS ⓘ municipal | 131 | 5% | High |
Moderate
Elevated concentration, not % above limit
|
|
| PFOA ⓘ municipal | 131 | 4% | High |
Moderate
Elevated concentration, not % above limit
|
|
| PFHxS ⓘ municipal | 131 | 3% | High |
Moderate
Elevated concentration, not % above limit
|
|
| Nitrate | 298 | 1% | High | Low | |
| Nitrite | 233 | 0% | High | Low | |
| Arsenic | 63 | 0% | Moderate | Low | |
| Fluoride | 258 | 0% | High | Low | |
| HFPO-DA (GenX) ⓘ municipal | 131 | 0% | High | Safe | |
| Lead | 59 | 0% | Moderate | Low | |
| PFNA ⓘ municipal | 131 | 0% | High | Low | |
| Radon | 16 | 0% | Moderate | Low ⓘ | |
| Uranium | 55 | 0% | Moderate | Low | |
| pH | 548 | — | High | Low | |
| Sodium | 207 | — | High | Low | |
| Hardness | 290 | — | High | Low | |
| PFBS ⓘ municipal | 131 | — | High | Low |
MCL = Maximum Contaminant Level (EPA limit for public water; used as benchmark for private wells). Distribution shows % of sampled wells in each concentration band. Methodology.
* Microbial contaminants (E. coli, coliform) reflect only samples from the last 10 years.
Data shows potential risk — a certified test confirms whether your water is affected.
Order a Tap Score Test →Population-level CDC data. Not individual risk prediction.
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