Groundwater in Rock County contains arsenic, lead, nitrate, pfoa, and sulfate at levels high enough to exceed EPA health standards. These contaminants are present at concerning concentrations that well owners should know about and have tested.
These contaminants come from a mix of sources. Arsenic, lead, and nitrate often seep into groundwater from natural rock breakdown, old plumbing, and farm runoff in this agricultural area. PFOA and sulfate are linked to industrial activity, road salt, and fertilizer use that has accumulated over time in the soil and rock layers below.
Groundwater in Rock County is very hard, driven by elevated calcium and magnesium from the bedrock below. The underlying rock dissolves slowly as water passes through it, adding these minerals to the water. Very hard water is common throughout wells in this county.
Arsenic, lead, nitrate, and PFOA have been found at levels exceeding EPA health standards in wells across Rock County. Arsenic can damage organs and increase cancer risk with long-term exposure. Lead harms brain development in children and can affect kidney and heart function in adults. Nitrate is particularly dangerous for infants and can interfere with oxygen in the blood. PFOA is a chemical that builds up in your body over time and may affect your immune system and liver.
The very hard water in this county's wells causes white scale buildup on faucets and in pipes and can shorten the lifespan of water heaters and dishwashers. You may notice spots on dishes and glasses even after washing, and soap does not lather easily. The moderate sulfate levels can give water a bitter taste and may cause loose stools in some people. Hard water also makes cleaning clothes and bathing more difficult.
We recommend testing your well water to find out what is actually in it, since every well is different and yours may have higher or lower levels than what is common in the county. Because several serious contaminants exceed health standards here, a comprehensive panel testing for metals, minerals, bacteria, and chemicals is recommended and typically costs between $200 and $400. Once you know what is in your water, you can choose treatments like reverse osmosis filters for contaminants or water softeners for hardness.
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 ⓘ |
|---|---|---|---|---|---|
| PFOA ⓘ municipal | 2 | 50% | Low | High ⓘ | |
| Sulfate | 51 | 26% | Moderate | High | |
| Lead | 17 | 19% | Moderate | High | |
| Arsenic | 40 | 10% | Moderate | Moderate | |
| Nitrate | 29 | 3% | Moderate |
Moderate
Elevated concentration, not % above limit
|
|
| HFPO-DA (GenX) ⓘ municipal | 1 | 0% | Low | Safe ⓘ | |
| PFHxS ⓘ municipal | 1 | 0% | Low | Safe ⓘ | |
| PFNA ⓘ municipal | 1 | 0% | Low | Safe ⓘ | |
| PFOS ⓘ municipal | 3 | 0% | Low | Low ⓘ | |
| Chloride | 56 | 0% | Moderate | Low | |
| Fluoride | 24 | 0% | Moderate | Low | |
| Nitrite | 12 | 0% | Low | Low | |
| pH | 13 | — | — | Low | Low |
| Sodium | 41 | — | — | Moderate | Low |
| Iron | 1 | 0% | Low | Safe ⓘ | |
| Manganese | 1 | 0% | Low | Safe ⓘ | |
| Fecal Coliform | 1 | 0% | Low | Safe ⓘ | |
| E. coli | 1 | 0% | Low | Safe ⓘ | |
| Total Coliform | 1 | 0% | Low | Safe ⓘ | |
| Hardness | 16 | — | — | Moderate | Low |
| PFBS ⓘ municipal | 1 | — | 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.
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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