Groundwater in Walworth County contains iron, manganese, arsenic, chloride, nitrate, and PFOA and PFOS. Several of these contaminants exceed EPA health standards, which means they warrant attention and testing.
These contaminants come from different sources. Iron and manganese dissolve naturally from the rock layers deep underground where groundwater sits in low-oxygen conditions. Arsenic also occurs naturally in the rock. Chloride and nitrate can enter from road salt and agricultural activity. PFOA and PFOS are human-made chemicals that have contaminated some wells through industrial or commercial sources.
Groundwater in this county is very hard, driven by elevated calcium and magnesium that dissolve from the limestone rock below. High iron is also present. As water moves slowly through these rock layers, it picks up these minerals in substantial amounts. Very hard water and elevated iron are found consistently across wells in this county.
Wells in Walworth County commonly contain arsenic, chloride, nitrate, and PFOA and PFOS at levels exceeding EPA health standards. Arsenic exposure over time can increase the risk of cancer and damage to the nervous system and kidneys. Nitrate is especially harmful to infants and can prevent blood from carrying oxygen properly. PFOA and PFOS are human-made chemicals that build up in the body and may affect the immune system, liver, and cholesterol levels. Chloride at elevated levels can be a concern for people on sodium-restricted diets.
The county's water is extremely hard, which causes white, crusty scale buildup on fixtures, faucets, and inside pipes. Iron at elevated levels leaves rust-colored stains on sinks, tubs, and clothing. This extreme hardness can shorten the lifespan of water heaters and dishwashers. Hard water also makes soap less effective for cleaning and bathing.
We recommend testing your well with a comprehensive metals and minerals panel, which typically costs $200-400. 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. Water softeners can reduce hardness, and arsenic removal filters or ion exchange systems can address specific 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 | 170 | 69% | High | High | |
| Manganese | 163 | 23% | High | High | |
| Arsenic | 23 | 17% | Moderate | High | |
| PFOA ⓘ municipal | 44 | 9% | Moderate | Moderate | |
| PFOS ⓘ municipal | 44 | 5% | Moderate |
Moderate
Elevated concentration, not % above limit
|
|
| Chloride | 156 | 3% | High |
Moderate
Elevated concentration, not % above limit
|
|
| Nitrate | 138 | 1% | High | Low | |
| Fluoride | 129 | 0% | High | Low | |
| HFPO-DA (GenX) ⓘ municipal | 44 | 0% | Moderate | Safe | |
| Lead | 23 | 0% | Moderate | Low | |
| Nitrite | 62 | 0% | Moderate | Low | |
| PFHxS ⓘ municipal | 44 | 0% | Moderate | Low | |
| PFNA ⓘ municipal | 44 | 0% | Moderate | Low | |
| Radon | 7 | 0% | Low | Low ⓘ | |
| Sulfate | 166 | 0% | High | Low | |
| Uranium | 19 | 0% | Moderate | Low | |
| Hardness | 172 | — | High | Low | |
| PFBS ⓘ municipal | 44 | — | Moderate | Low | |
| pH | 186 | — | High | Low | |
| Sodium | 102 | — | High | 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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