Madison County's groundwater contains manganese, iron, radon, chloride, and sulfate. Several of these contaminants exceed EPA health standards and warrant attention from well owners.
These contaminants come from the sandstone rock beneath the county. As groundwater moves through sandstone, it dissolves minerals like iron and manganese naturally present in the rock. Radon seeps from radioactive elements embedded in the sandstone. Chloride and sulfate can also enter from road salt and agricultural activity on the land above.
Groundwater in this county is very hard, driven by elevated calcium and magnesium from the sandstone aquifer. The sandstone here releases these hardness minerals as water passes through over time. Very hard water is widespread across Madison County wells based on the data available.
Wells in Madison County commonly exceed EPA health standards for chloride, iron, manganese, radon, and sulfate. Radon is a radioactive gas that enters groundwater from rock and can accumulate in homes, posing a serious lung cancer risk over time. Manganese at elevated levels can affect the nervous system, particularly in children and infants. Chloride and iron at these concentrations can also present health concerns with long-term exposure.
The very hard water in county wells creates noticeable quality-of-life problems. You may see rust-colored stains on laundry, dishes, and fixtures from iron. Hard water leaves scale buildup inside pipes and on appliances like water heaters and dishwashers, which can shorten their lifespan. Some people notice a metallic or slightly unpleasant taste in the water.
We recommend testing your well because every well is different and yours may have higher or lower levels than what is common in the county. 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 between $200 and $400. Treatment options like radon ventilation systems and water softeners can address multiple concerns once you understand your specific water composition.
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 ⓘ |
|---|---|---|---|---|---|
| Manganese | 29 | 24% | Moderate | High | |
| Iron | 29 | 21% | Moderate | High | |
| Radon | 18 | 17% | Moderate | High ⓘ | |
| Sulfate | 29 | 14% | Moderate | Moderate | |
| Chloride | 29 | 3% | Moderate |
Moderate
Elevated concentration, not % above limit
|
|
| Arsenic | 27 | 0% | Moderate | Low | |
| Fluoride | 29 | 0% | Moderate | Low | |
| HFPO-DA (GenX) ⓘ municipal | 16 | 0% | Moderate | Safe | |
| Lead | 27 | 0% | Moderate | Low | |
| Nitrate | 29 | 0% | Moderate | Low | |
| Nitrite | 21 | 0% | Moderate | Low | |
| PFHxS ⓘ municipal | 16 | 0% | Moderate | Safe | |
| PFNA ⓘ municipal | 16 | 0% | Moderate | Safe | |
| PFOA ⓘ municipal | 16 | 0% | Moderate | Safe | |
| PFOS ⓘ municipal | 16 | 0% | Moderate | Safe | |
| Uranium | 18 | 0% | Moderate | Low | |
| Total Coliform | 39* | 0% | Moderate | Low | |
| Sodium | 27 | — | Moderate | Low | |
| pH | 63 | — | Moderate | Low | |
| PFBS ⓘ municipal | 16 | — | Moderate | Safe | |
| Hardness | 29 | — | Moderate | Low | |
| Fecal Coliform | 5* | 0% | Low | Low ⓘ | |
| E. coli | 36* | 0% | Moderate | 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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