Groundwater in Kewaunee County contains iron, sulfate, and arsenic that well owners should know about. Iron and sulfate exceed EPA health standards, making them the primary concerns in this area.
Iron and sulfate come from the rock layers beneath the county. As groundwater sits in contact with these minerals underground, they dissolve into the water naturally. Arsenic also occurs naturally in the local rock and releases into water as it moves slowly through the ground.
Groundwater in this county is very hard, driven mainly by calcium and magnesium from the underlying rock. The high hardness level is common across wells here because water stays in contact with mineral-rich layers for extended periods. Most wells in Kewaunee County show this same very hard water character along with elevated iron.
Wells in Kewaunee County commonly contain iron and sulfate at levels exceeding EPA health standards. Long-term exposure to elevated iron can affect children's development and overall health. Sulfate at these levels may cause digestive issues, especially in infants and people with certain health conditions.
The very hard water in county wells leaves white, crusty scale on faucets, fixtures, and inside pipes. Iron causes orange-brown staining on sinks, toilets, and laundry that is difficult to remove. This extreme hardness can shorten the lifespan of water heaters and dishwashers. You may also notice a metallic or unpleasant taste in your water.
We recommend testing your well water through a state-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 it can be properly treated. A comprehensive metals and minerals panel typically costs $200-400 and can guide treatment choices like iron filters or water softeners.
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 | 36 | 50% | Moderate | High | |
| Sulfate | 35 | 3% | Moderate | Low | |
| Arsenic | 1 | 0% | Low | Low ⓘ | |
| Chloride | 35 | 0% | Moderate | Low | |
| Fluoride | 26 | 0% | Moderate | Low | |
| HFPO-DA (GenX) | 2 | 0% | Low | Safe ⓘ | |
| Lead | 1 | 0% | Low | Safe ⓘ | |
| Manganese | 35 | 0% | Moderate | Low | |
| Nitrate | 23 | 0% | Moderate | Low | |
| Nitrite | 11 | 0% | Low | Low | |
| PFHxS | 2 | 0% | Low | Low ⓘ | |
| PFNA | 2 | 0% | Low | Safe ⓘ | |
| PFOA | 2 | 0% | Low | Low ⓘ | |
| PFOS | 2 | 0% | Low | Low ⓘ | |
| Hardness | 37 | — | Moderate | Low | |
| PFBS | 2 | — | Low | Safe ⓘ | |
| pH | 32 | — | Moderate | Low | |
| Sodium | 12 | — | 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.
* 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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