Brown County groundwater contains iron, radon, chloride, arsenic, lead, manganese, nitrate, and sulfate. Multiple contaminants exceed EPA health standards, making this a county where well owners should test their water.
The deep rock layers beneath Brown County naturally release iron, arsenic, lead, and manganese as groundwater slowly moves through them. Radon seeps from radioactive elements in the bedrock. Chloride and nitrate enter from road salt and fertilizer use on the land above.
Groundwater in this county is very hard, driven by elevated calcium and magnesium dissolving from the limestone and dolomite rock below. High iron concentrations also make the water notably mineral-rich. These hard-water and iron characteristics show up across most wells in the county.
Wells in Brown County commonly have arsenic, lead, radon, nitrate, and manganese above EPA health standards. Arsenic and lead build up in your body over time and damage organs and nerves. Lead is especially harmful to children's brain development. Radon is a radioactive gas that increases lung cancer risk when you breathe it in. Nitrate and manganese can also cause health problems with long-term exposure.
The very hard water in county wells leaves white, crusty scale on pipes and fixtures. Iron causes orange-brown staining on sinks, bathtubs, and laundry. You may notice a metallic taste or rotten-egg smell. This extreme hardness can shorten the lifespan of water heaters and dishwashers. Hard water also makes soap less effective for cleaning.
We recommend a comprehensive water test since your well is different from others in the county and may have higher or lower levels of these contaminants. Testing is the only way to know what is actually in your water so it can be properly treated. A comprehensive metals and minerals panel typically costs $200-400, plus a separate radon test. Depending on your results, treatment options include water softeners, activated carbon filters, or radon ventilation systems.
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 | 158 | 51% | High | High | |
| Radon | 6 | 17% | Low | High ⓘ | |
| Chloride | 265 | 15% | High | Moderate | |
| Manganese | 157 | 13% | High | Moderate | |
| Sulfate | 269 | 8% | High | Moderate | |
| Arsenic | 68 | 1% | Moderate | Low | |
| Lead | 68 | 1% | Moderate | Low | |
| Nitrate | 179 | 1% | High | Low | |
| Uranium | 8 | 0% | Low | Low ⓘ | |
| PFOS ⓘ municipal | 54 | 0% | Moderate | Safe | |
| PFOA ⓘ municipal | 54 | 0% | Moderate | Low | |
| PFNA ⓘ municipal | 54 | 0% | Moderate | Low | |
| PFHxS ⓘ municipal | 54 | 0% | Moderate | Safe | |
| Nitrite | 161 | 0% | High | Low | |
| HFPO-DA (GenX) ⓘ municipal | 54 | 0% | Moderate | Safe | |
| Fluoride | 142 | 0% | High | Low | |
| PFBS ⓘ municipal | 54 | — | Moderate | Safe | |
| Hardness | 268 | — | High | Low | |
| Sodium | 206 | — | High | Low | |
| pH | 270 | — | 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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