Groundwater in Marquette County contains iron, manganese, and arsenic as the primary contaminants well owners should know about. Iron and manganese exceed EPA health standards, and arsenic also exceeds its limit, making these serious concerns that require testing and likely treatment.
The Jacobsville aquifer beneath the county is made of reddish sandstone that naturally contains these metals locked within the rock itself. As groundwater moves slowly through cracks and spaces in this stone, iron and manganese dissolve into the water. Arsenic occurs naturally in trace amounts within certain minerals in the same rock formation.
Groundwater in this county is moderately hard, driven by dissolved calcium and magnesium from the sandstone and the minerals it contains. The moderate iron concentration reflects how these metals are packed into the local bedrock and gradually leach into water as it passes through. Elevated iron and manganese are common findings across wells in Marquette County.
Wells in Marquette County commonly exceed EPA health standards for arsenic, iron, manganese, and nitrate. Arsenic can damage your skin, bladder, and lungs with long-term exposure. Iron and manganese can build up in your body and affect how your organs work. Manganese is especially concerning for children because it can harm brain development. Nitrate in drinking water can be dangerous for babies and pregnant women.
Wells in this county are moderately hard, which means you may see white scale buildup on pipes and fixtures over time. Iron causes orange or rust-colored stains on sinks, toilets, and laundry that are hard to remove. You might notice a metallic or bitter taste in the water. Hard water can also shorten the lifespan of water heaters and dishwashers.
We recommend testing your well water through a certified lab. Every well is different, and your well 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 you can treat it properly. A comprehensive metals and minerals panel typically runs $200-400 and can identify all the contaminants present. Iron removal systems and water softeners can help address these concerns once you know your specific results.
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 | 67 | 33% | Moderate | High | |
| Manganese | 67 | 16% | Moderate | High | |
| Arsenic | 41 | 7% | Moderate | Moderate | |
| Nitrate | 147 | 1% | High | Low | |
| Chloride | 148 | 0% | High | Low | |
| Fluoride | 66 | 0% | Moderate | Low | |
| HFPO-DA (GenX) ⓘ municipal | 10 | 0% | Low | Safe | |
| Lead | 43 | 0% | Moderate | Low | |
| Nitrite | 63 | 0% | Moderate | Low | |
| PFHxS ⓘ municipal | 10 | 0% | Low | Safe | |
| PFNA ⓘ municipal | 10 | 0% | Low | Safe | |
| PFOA ⓘ municipal | 12 | 0% | Low | Safe | |
| PFOS ⓘ municipal | 10 | 0% | Low | Safe | |
| Radon | 8 | 0% | Low | Low ⓘ | |
| Sulfate | 148 | 0% | High | Low | |
| Uranium | 28 | 0% | Moderate | Low | |
| Hardness | 147 | — | High | Low | |
| PFBS ⓘ municipal | 10 | — | Low | Safe | |
| pH | 153 | — | High | Low | |
| Sodium | 65 | — | 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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