Radon, iron, and manganese are present in Trempealeau County groundwater and all three exceed EPA health standards. Iron levels are very high, while radon and manganese are at concerning concentrations that warrant attention.
The deep limestone and sandstone rock layers beneath the county naturally contain these metals and radioactive elements. As water moves slowly through these rocks over time, iron and manganese dissolve into the groundwater. Radon forms from the natural breakdown of uranium present in the bedrock.
Groundwater in this county is moderately hard, driven by elevated iron that distinguishes the water's character. The rock layers that supply wells release iron as acidic groundwater passes through them over years. Very high iron is common across wells in the county, though individual wells vary in how much they contain.
Wells in Trempealeau County commonly contain iron, manganese, radon, and sulfate at levels that exceed EPA health standards. Radon is a radioactive gas that can increase lung cancer risk when breathed over many years. Iron and manganese can affect how your body absorbs nutrients and may impact children's brain development at elevated levels. These contaminants come from the natural bedrock beneath the county.
County wells are moderately hard, which means you may notice rusty-brown stains on clothes and fixtures from the high iron content. The water might taste metallic or have an unpleasant odor. Hard water also builds up scale on pipes and inside appliances like water heaters and dishwashers, which can shorten their lifespan over time.
We recommend testing your well with a comprehensive metals and minerals panel to find out exactly what is in your water, since every well is different and yours could have higher or lower levels than what is common in the county. Testing is the only way to know what needs to be treated. A full panel typically costs between $200 and $400. Iron removal systems and radon ventilation can help address the main concerns.
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 ⓘ |
|---|---|---|---|---|---|
| Radon | 1 | 100% | Low | High ⓘ | |
| Iron | 86 | 88% | Moderate | High | |
| Manganese | 86 | 69% | Moderate | High | |
| Sulfate | 70 | 1% | Moderate | Low | |
| Arsenic | 5 | 0% | Low | Low ⓘ | |
| Chloride | 70 | 0% | Moderate | Low | |
| Fluoride | 63 | 0% | Moderate | Low | |
| HFPO-DA (GenX) | 5 | 0% | Low | Safe ⓘ | |
| Lead | 5 | 0% | Low | Safe ⓘ | |
| Nitrate | 44 | 0% | Moderate | Low | |
| Nitrite | 36 | 0% | Moderate | Low | |
| PFHxS | 5 | 0% | Low | Low ⓘ | |
| PFNA | 5 | 0% | Low | Low ⓘ | |
| PFOA | 5 | 0% | Low | Low ⓘ | |
| PFOS | 5 | 0% | Low | Safe ⓘ | |
| Uranium | 3 | 0% | Low | Safe ⓘ | |
| pH | 77 | — | Moderate | Low | |
| Sodium | 29 | — | Moderate | Low | |
| Hardness | 84 | — | Moderate | Low | |
| PFBS | 5 | — | Low | 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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