Groundwater in Rock County contains iron, manganese, nitrate, and PFOA at levels that exceed EPA health standards and warrant attention. These contaminants are present at concentrations serious enough that well owners should be aware of them and consider testing.
Iron and manganese occur naturally in the deep limestone and sandstone rock layers beneath the county. Nitrate enters from fertilizers and septic systems on the surface, then seeps down into the groundwater. PFOA is a human-made chemical used in industrial processes that can contaminate water when released into the environment. All of these contaminants travel through the porous rock to reach private wells.
Groundwater in Rock County is very hard, driven by elevated calcium and magnesium that dissolve from the limestone as water moves slowly through it underground. Hard water is the standard across wells throughout this county and the surrounding region.
Wells in Rock County commonly contain iron, manganese, nitrate, and PFOA at levels above EPA health standards. Iron and manganese at elevated levels can affect blood production and organ function over time. Nitrate poses risks to infants and can interfere with oxygen in the bloodstream. PFOA is a human-made chemical that accumulates in the body and has been linked to health concerns at high exposures.
Rock County has very hard water, which leaves white scale buildup on faucets, fixtures, and inside pipes. The hardness can shorten the lifespan of water heaters, dishwashers, and washing machines. You may also notice that soap is less effective and that your hair feels sticky after washing.
We recommend testing your well water since 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. Because multiple contaminants exceed health standards here, a comprehensive metals and minerals panel is recommended, which typically costs $200 to $400. Water softeners can help with hardness, and specific treatments exist for iron, manganese, and other contaminants.
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 | 104 | 18% | High | High | |
| Manganese | 101 | 12% | High | Moderate | |
| Nitrate | 93 | 8% | Moderate | Moderate | |
| PFOA ⓘ municipal | 48 | 2% | Moderate | Low | |
| Arsenic | 9 | 0% | Low | Low ⓘ | |
| Chloride | 107 | 0% | High | Low | |
| Fluoride | 87 | 0% | Moderate | Low | |
| HFPO-DA (GenX) ⓘ municipal | 48 | 0% | Moderate | Safe | |
| Lead | 9 | 0% | Low | Safe ⓘ | |
| Nitrite | 56 | 0% | Moderate | Low | |
| PFHxS ⓘ municipal | 48 | 0% | Moderate | Low | |
| PFNA ⓘ municipal | 48 | 0% | Moderate | Low | |
| PFOS ⓘ municipal | 48 | 0% | Moderate | Low | |
| Sulfate | 106 | 0% | High | Low | |
| Uranium | 4 | 0% | Low | Low ⓘ | |
| Hardness | 108 | — | High | Low | |
| PFBS ⓘ municipal | 48 | — | Moderate | Low | |
| pH | 115 | — | High | Low | |
| Sodium | 68 | — | 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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