Groundwater in Madison County contains iron, manganese, and arsenic. Iron and arsenic exceed EPA health standards, making these contaminants a concern for well owners.
These metals come from the rock layers beneath the county. The limestone and other bedrock here naturally contain iron and manganese. Arsenic hides in certain layers of shale mixed with the limestone. As groundwater moves slowly through cracks in this rock, these metals dissolve into the water over time.
Groundwater in Madison County is very hard, driven by elevated calcium and magnesium from the limestone below. The same rock that produces hardness also releases iron into the water. These characteristics are widespread across wells in the county.
Wells in Madison County commonly contain iron, arsenic, sulfate, and manganese at levels that exceed EPA health standards. Arsenic is especially serious because it is colorless and odorless--you cannot taste or see it. Long-term exposure to arsenic increases the risk of cancer and can damage your kidneys and digestive system. Manganese at elevated levels can harm brain development and nervous system function in children and adults. Iron and sulfate also pose health concerns at the concentrations found in county wells.
The water in Madison County is extremely hard, which means you will see thick white crusty buildup on faucets, showerheads, and inside pipes. Iron stains sinks, toilets, and laundry orange-brown. High sulfate levels can give water a bitter taste and may cause digestive issues. Extreme hardness like this can shorten the lifespan of water heaters and dishwashers by years. You may also notice a metallic taste in your water.
We recommend testing your well with a comprehensive metals and minerals panel because every well is different--your water 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 well so it can be properly treated. A comprehensive panel typically costs $200-400. Treatment options like water softeners combined with iron and arsenic removal systems can address multiple contaminants at once.
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 | 91 | 99% | Moderate | High | |
| Manganese | 91 | 29% | Moderate | High | |
| Sulfate | 9 | 22% | Low | High ⓘ | |
| Arsenic | 84 | 17% | Moderate | High | |
| Lead | 84 | 5% | Moderate |
Moderate
Elevated concentration, not % above limit
|
|
| Chloride | 89 | 0% | Moderate | Low | |
| Fluoride | 72 | 0% | Moderate | Low | |
| HFPO-DA (GenX) ⓘ municipal | 8 | 0% | Low | Safe ⓘ | |
| Nitrate | 1 | 0% | Low | Low ⓘ | |
| Nitrite | 9 | 0% | Low | Low ⓘ | |
| PFHxS ⓘ municipal | 8 | 0% | Low | Safe ⓘ | |
| PFNA ⓘ municipal | 8 | 0% | Low | Safe ⓘ | |
| PFOA ⓘ municipal | 8 | 0% | Low | Safe ⓘ | |
| PFOS ⓘ municipal | 8 | 0% | Low | Safe ⓘ | |
| Hardness | 77 | — | Moderate | Low | |
| PFBS ⓘ municipal | 8 | — | Low | Safe ⓘ | |
| pH | 77 | — | Moderate | Low | |
| Sodium | 91 | — | 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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