Groundwater in Milwaukee County contains iron, chloride, sulfate, arsenic, lead, and PFOA at levels that exceed EPA health standards. These contaminant levels are serious and require testing and treatment.
The limestone and rock layers beneath Milwaukee County naturally release iron, sulfate, and hardness minerals into groundwater as water moves slowly through them. Chloride enters from road salt applied during winter months. Arsenic and lead occur naturally in the bedrock. Low-oxygen conditions deep underground speed up the release of these metals into the water.
Groundwater in this county is moderately hard and high in iron and sodium, driven by calcium, magnesium, and iron from the rock below. As water passes through limestone and other rock layers, these minerals dissolve and concentrate in the water. These characteristics are common across wells throughout the county.
Wells in Milwaukee County commonly contain arsenic, lead, and PFOA at levels above EPA health standards. Arsenic raises the risk of cancer and organ damage with long-term exposure. Lead harms brain development in children and can damage kidneys and nerves in adults. PFOA is a chemical linked to thyroid disease, liver damage, and immune system problems. Chloride and sulfate also exceed standards in county wells and pose health risks.
Wells in this county have moderately hard water with high iron and sodium. The high iron causes orange and brown staining on sinks, toilets, and laundry. Hard water leaves white crusty buildup on fixtures and reduces how well soap works. The combination of these minerals can shorten the lifespan of water heaters and dishwashers.
We recommend a comprehensive metals and minerals panel test for your well. 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 you can treat it properly. A comprehensive panel typically costs between $200 and $400 and will guide treatment options like arsenic removal systems, water softeners, and iron filters.
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 | 164 | 66% | High | High | |
| Sulfate | 180 | 32% | High | High | |
| Manganese | 159 | 10% | High | Moderate | |
| Chloride | 180 | 1% | High | Low | |
| Arsenic | 12 | 0% | Low | Low | |
| Fluoride | 163 | 0% | High | Low | |
| HFPO-DA (GenX) ⓘ municipal | 61 | 0% | Moderate | Safe | |
| Lead | 12 | 0% | Low | Safe | |
| Nitrate | 107 | 0% | High | Low | |
| Nitrite | 63 | 0% | Moderate | Low | |
| PFHxS ⓘ municipal | 61 | 0% | Moderate | Low | |
| PFNA ⓘ municipal | 61 | 0% | Moderate | Safe | |
| PFOA ⓘ municipal | 61 | 0% | Moderate | Safe | |
| PFOS ⓘ municipal | 61 | 0% | Moderate | Safe | |
| Radon | 1 | 0% | Low | Low ⓘ | |
| Uranium | 11 | 0% | Low | Low | |
| Hardness | 181 | — | High | Low | |
| PFBS ⓘ municipal | 61 | — | Moderate | Low | |
| pH | 184 | — | High | Low | |
| Sodium | 110 | — | 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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