Groundwater in Madison County contains radon, manganese, and nitrite at levels that exceed EPA health standards. These contaminants are present at concentrations the EPA considers a concern for human health and warrant attention from well owners.
Radon seeps into groundwater from uranium naturally present in the rock below. Manganese and nitrite come from different sources--manganese occurs naturally in the basin rock, while nitrite enters groundwater from septic systems and agricultural land where nitrogen fertilizers or animal waste break down underground. The Early Mesozoic basin rock that holds water in this county tends to release both manganese and radon into wells.
Groundwater in this county is soft and low in iron, with very little sulfate or sodium. The basin rock does not contain large amounts of minerals that dissolve into water, so wells here stay relatively free of the hardening minerals found in limestone areas. Most wells in Madison County show this soft, low-mineral character throughout the region.
Wells in Madison County sometimes contain manganese, nitrite, and radon at levels that exceed EPA health standards. Manganese can affect the nervous system with long-term exposure, especially in children. Nitrite prevents blood from carrying oxygen properly. Radon is a radioactive gas that increases lung cancer risk when breathed in over time.
The good news is that mineral levels in county wells are generally low. You probably will not see staining, scale buildup, or odd tastes or smells from minerals. Your water heater and other appliances should not experience shortened lifespans from mineral damage.
We recommend testing your well water to find out what is actually in it, since every well is different and yours could have higher or lower levels than what is common in the county. A comprehensive panel that checks for metals, minerals, and bacteria costs between $200 and $400 and is the best way to know exactly what you are dealing with. Testing is the only way to figure out what treatment your well needs, whether that is a water softener, filter, or aeration system.
| Contaminant | Samples ⓘ | % Above MCL ⓘ | Distribution ⓘ | Confidence ⓘ | Risk ⓘ |
|---|---|---|---|---|---|
| Radon | 1 | 0% | Low | Low ⓘ | |
| Sulfate | 1 | 0% | Low | Low ⓘ | |
| PFOA ⓘ municipal | 1 | 0% | Low | Safe ⓘ | |
| PFNA ⓘ municipal | 1 | 0% | Low | Safe ⓘ | |
| PFOS ⓘ municipal | 1 | 0% | Low | Safe ⓘ | |
| Uranium | 1 | 0% | Low | Safe ⓘ | |
| Lead | 1 | 0% | Low | Safe ⓘ | |
| Manganese | 1 | 0% | Low | Safe ⓘ | |
| Iron | 1 | 0% | Low | Safe ⓘ | |
| PFHxS ⓘ municipal | 1 | 0% | Low | Safe ⓘ | |
| Arsenic | 1 | 0% | Low | Low ⓘ | |
| Chloride | 1 | 0% | Low | Low ⓘ | |
| Fluoride | 1 | 0% | Low | Low ⓘ | |
| HFPO-DA (GenX) ⓘ municipal | 1 | 0% | Low | Safe ⓘ | |
| Hardness | 1 | — | Low | Low ⓘ | |
| PFBS ⓘ municipal | 1 | — | Low | Safe ⓘ | |
| 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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