Radon, arsenic, and chloride are present in Madison County groundwater. Radon is the only contaminant here that exceeds EPA health standards, reaching levels of concern, while arsenic and chloride are detected but remain below the limits set to protect health.
Radon seeps into groundwater from uranium naturally found in the surrounding rock. Arsenic also occurs naturally in the Valley and Ridge bedrock that supplies wells across this county. Chloride can enter through road salt and natural mineral deposits in the soil and rock layers.
Groundwater in this county is moderately hard, driven by calcium and magnesium from the bedrock below. These minerals accumulate as water passes through the limestone and other rock layers that make up the Valley and Ridge aquifers in the area. Moderate hardness is common across wells throughout Madison County.
Radon is the main health concern in wells across Madison County. Radon is a radioactive gas that comes from underground rock and can build up in your home over time. Breathing radon increases your risk of lung cancer. Arsenic and chloride are also found in some county wells and deserve attention, though they appear at lower levels in most cases.
The water in this county is moderately hard, which means you might see some scale buildup on faucets and showerheads or notice spots on dishes after they dry. Hard water can make soap less effective and shorten the lifespan of appliances like water heaters and dishwashers. Your water should taste fine, and the sodium and sulfate levels are low, so you won't experience salty or rotten-egg tastes.
Since every well is different, your water could have higher or lower levels of radon, arsenic, and chloride than what is common in the county. Testing is the only way to know what is actually in your well so you can treat it if needed. We recommend a comprehensive metals and minerals panel that includes radon testing, which costs between two hundred and four hundred dollars. Radon can be removed with aeration systems, and arsenic responds well to activated carbon filters.
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 ⓘ | |
| Arsenic | 1 | 0% | Low | Safe ⓘ | |
| Chloride | 1 | 0% | Low | Low ⓘ | |
| Fluoride | 1 | 0% | Low | Low ⓘ | |
| Iron | 1 | 0% | Low | Safe ⓘ | |
| Lead | 1 | 0% | Low | Low ⓘ | |
| Manganese | 1 | 0% | Low | Safe ⓘ | |
| Nitrate | 1 | 0% | Low | Low ⓘ | |
| Nitrite | 1 | 0% | Low | Safe ⓘ | |
| Sulfate | 1 | 0% | Low | Low ⓘ | |
| Uranium | 1 | 0% | Low | Low ⓘ | |
| Hardness | 1 | — | Low | Low ⓘ | |
| pH | 1 | — | Low | Low ⓘ | |
| Sodium | 1 | — | 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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