Groundwater in Hillsdale County contains arsenic, iron, manganese, nitrite, radon, and sulfate at levels that exceed EPA health standards. These contaminant levels are concerning and require attention.
The Marshall aquifer here is made of mixed rock layers that naturally release iron and manganese when groundwater sits in contact with them for long periods. Arsenic is locked inside the rock itself. Nitrite enters from fertilizer and septic systems used across the county. Radon comes from the rock decay happening naturally underground.
Groundwater in this county is notably hard, driven by elevated iron and manganese that concentrate in the water as it moves slowly through these rock layers. Most wells in Hillsdale County show these same mineral characteristics.
Wells in Hillsdale County commonly contain arsenic, iron, manganese, nitrite, radon, and sulfate at levels that exceed EPA health standards. Arsenic is a poison that increases cancer risk with long-term exposure. Manganese damages brain development in children and can affect memory and thinking in adults. Nitrite interferes with how blood carries oxygen, which is especially dangerous for infants. Radon is a radioactive gas that increases lung cancer risk over time. Iron and sulfate themselves are not regulated for health, but they contribute to the overall contamination burden in your well.
Beyond health concerns, the mineral content in county wells creates quality-of-life problems. Iron stains sinks, toilets, and laundry orange or brown. Sulfate gives water a bitter or rotten-egg taste and odor. The combination of these minerals builds scale inside pipes, water heaters, and dishwashers, shortening the lifespan of appliances and plumbing.
We recommend testing your well because every well is different and 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. Since multiple contaminants exceed health standards here, we recommend a comprehensive metals and minerals panel, which typically costs two hundred to four hundred dollars. Treatment options like oxidation filters combined with arsenic-removal systems or reverse osmosis 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 | 31 | 74% | Moderate | High | |
| Manganese | 31 | 45% | Moderate | High | |
| Arsenic | 20 | 5% | Moderate | Moderate | |
| Nitrate | 27 | 4% | Moderate |
Moderate
Elevated concentration, not % above limit
|
|
| Sulfate | 31 | 3% | Moderate |
Moderate
Elevated concentration, not % above limit
|
|
| Chloride | 31 | 0% | Moderate | Low | |
| Fluoride | 30 | 0% | Moderate | Low | |
| HFPO-DA (GenX) ⓘ municipal | 3 | 0% | Low | Safe ⓘ | |
| Lead | 14 | 0% | Low | Low | |
| Nitrite | 27 | 0% | Moderate | Low | |
| PFHxS ⓘ municipal | 2 | 0% | Low | Safe ⓘ | |
| PFNA ⓘ municipal | 3 | 0% | Low | Safe ⓘ | |
| PFOA ⓘ municipal | 3 | 0% | Low | Safe ⓘ | |
| PFOS ⓘ municipal | 2 | 0% | Low | Safe ⓘ | |
| Radon | 6 | 0% | Low | Low ⓘ | |
| Uranium | 14 | 0% | Low | Low | |
| Total Coliform | 3* | 0% | Low | Low ⓘ | |
| Sodium | 31 | — | Moderate | Low | |
| pH | 33 | — | Moderate | Low | |
| PFBS ⓘ municipal | 2 | — | Low | Safe ⓘ | |
| Hardness | 31 | — | Moderate | Low | |
| E. coli | 3* | 0% | Low | Safe ⓘ |
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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