Groundwater in Ozaukee County contains iron, manganese, and sulfate that exceed EPA health standards, along with concerning PFAS chemicals including PFOA, PFOS, and PFHXS. These contaminant levels are serious enough to warrant testing and treatment.
Iron and manganese dissolve naturally from the limestone and dolomite rock layers beneath the county as groundwater moves slowly through oxygen-poor conditions underground. Sulfate also leaches from these same stone layers. PFAS chemicals enter from industrial sources, landfills, and firefighting foam used at airports and military sites in the region.
Groundwater in this county is very hard, driven by elevated calcium and magnesium from the limestone bedrock below. This extreme hardness develops as water passes through and dissolves these stone layers over time. Very hard water is common across wells throughout Ozaukee County.
Wells in Ozaukee County commonly contain iron, manganese, and PFOA and PFOS at levels that exceed EPA health standards. Manganese can harm brain development in children and infants at elevated levels. Iron itself is not directly toxic, but PFOA and PFOS are synthetic chemicals linked to serious health concerns including immune system effects and developmental problems. Sulfate at the levels found here can cause digestive issues in some people.
The extremely hard water in this county leaves white, crusty scale buildup on pipes, faucets, and fixtures. Iron causes orange and brown staining on sinks, toilets, and laundry. The water may taste slightly metallic or bitter from sulfate. This extreme hardness can shorten the lifespan of water heaters, dishwashers, and other appliances.
We recommend a comprehensive metals and minerals panel since multiple contaminants exceed standards in county wells. Testing costs between $200-400 and is the only way to know what is actually in your well so it can be treated properly. Every well is different, and your well may have higher or lower levels than what is common in the county. Treatment options like iron filters, water softeners, and PFAS removal systems can address these concerns.
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 | 101 | 42% | High | High | |
| Sulfate | 104 | 16% | High | High | |
| Manganese | 101 | 11% | High | Moderate | |
| PFHxS ⓘ municipal | 45 | 9% | Moderate | Moderate | |
| PFOS ⓘ municipal | 45 | 9% | Moderate | Moderate | |
| PFOA ⓘ municipal | 45 | 2% | Moderate | Low | |
| Nitrate | 74 | 0% | Moderate | Low | |
| Nitrite | 71 | 0% | Moderate | Low | |
| PFNA ⓘ municipal | 45 | 0% | Moderate | Safe | |
| Radon | 1 | 0% | Low | Low ⓘ | |
| Uranium | 5 | 0% | Low | Low ⓘ | |
| Arsenic | 3 | 0% | Low | Low ⓘ | |
| Chloride | 104 | 0% | High | Low | |
| Fluoride | 97 | 0% | Moderate | Low | |
| HFPO-DA (GenX) ⓘ municipal | 45 | 0% | Moderate | Safe | |
| Lead | 3 | 0% | Low | Low ⓘ | |
| Hardness | 104 | — | High | Low | |
| PFBS ⓘ municipal | 45 | — | Moderate | Low | |
| pH | 77 | — | Moderate | Low | |
| Sodium | 81 | — | 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.
Loading recent water news…