Well Water in Madison County: What to Test and Why

High Risk
Testing Strongly Recommended 9347 samples analyzed
Top Concerns in This County
Iron Manganese Arsenic

Why This Happens Here

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.

What This Means for You

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 Detection Data

Contaminant Samples % Above MCL Distribution Confidence Risk
Iron 74 63% 26% · 12% · 62% Moderate High
Manganese 47 52% 28% · 21% · 51% Moderate High
Arsenic 10 33% 40% · 30% · 30% Low High
Sulfate 45 4% 78% · 18% · 4% Moderate Moderate
Elevated concentration, not % above limit
HFPO-DA (GenX) ⓘ municipal 8 0% 100% · 0% · 0% Low Safe
Chloride 24 0% 100% · 0% · 0% Moderate Low
PFOA ⓘ municipal 8 0% 100% · 0% · 0% Low Safe
PFOS ⓘ municipal 8 0% 100% · 0% · 0% Low Safe
PFNA ⓘ municipal 8 0% 100% · 0% · 0% Low Safe
PFHxS ⓘ municipal 8 0% 100% · 0% · 0% Low Safe
Fluoride 18 0% 83% · 17% · 0% Moderate Low
Nitrate 2 0% 100% · 0% · 0% Low Low
Lead 1 0% 100% · 0% · 0% Low Safe
Nitrite 1 0% 100% · 0% · 0% Low Safe
Hardness 25 Moderate Low
PFBS ⓘ municipal 8 100% · 0% · 0% Low Safe
Sodium 50 Moderate Low
pH 7 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.

Data shows potential risk — a certified test confirms whether your water is affected.

Order a Tap Score Test →

Population Health Context

Population-level CDC data. Not individual risk prediction.

6.1%
Cancer Prevalence
(state avg: 6.8%)
2.7%
Kidney Disease Rate
(state avg: 3.1%)

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