Groundwater in Olmsted County contains iron, manganese, nitrate, chloride, lead, and PFNA. Several of these contaminants exceed EPA health standards and warrant attention.
The limestone bedrock beneath this county naturally releases iron, manganese, and hardness-causing minerals into water as it flows underground. Nitrate and chloride come from land use above--fertilizers, manure, and road salt seep down through soil into the water supply. Lead enters from old plumbing and service lines. PFNA is a human-made chemical that has contaminated some wells, likely from industrial or commercial sources.
Groundwater in this county is very hard, driven by calcium and magnesium that dissolve from the limestone rock. The same limestone geology that creates hardness also naturally contributes iron and manganese to the water. These characteristics are widespread across wells in Olmsted County.
Wells in Olmsted County commonly exceed EPA health standards for chloride, iron, lead, manganese, nitrate, and PFNA. Lead is especially harmful to children and can damage their developing brains and organs. Nitrate poses serious risks to infants and pregnant women. Manganese at elevated levels can affect the nervous system. Chloride, iron, and PFNA also carry health concerns at elevated concentrations.
The county's water is very hard, which creates real problems in your home. You will see white crusty scale buildup on faucets, showerheads, and inside pipes. Iron stains fixtures and laundry orange or brown. Hard water reduces how well soap lathers and leaves spots on dishes. This extreme hardness also wears out water heaters and dishwashers faster than normal.
We recommend a comprehensive metals and minerals panel to find out what is actually in your well, since every well is different and your water may have higher or lower levels than what is common here. Testing is the only way to know what needs treatment. A full panel typically costs between two hundred and four hundred dollars. Water softeners, iron removal systems, and nitrate treatment can address different 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 | 368 | 25% | High | High | |
| Manganese | 262 | 10% | High | Moderate | |
| Nitrate | 200 | 6% | High | Moderate | |
| Lead | 222 | 2% | High | Low | |
| Chloride | 452 | 2% | High | Low | |
| PFNA ⓘ municipal | 79 | 1% | Moderate | Low | |
| Arsenic | 222 | 0% | High | Low | |
| Uranium | 1 | 0% | Low | Low ⓘ | |
| Fluoride | 191 | 0% | High | Low | |
| Sulfate | 357 | 0% | High | Low | |
| Nitrite | 162 | 0% | High | Low | |
| PFHxS ⓘ municipal | 68 | 0% | Moderate | Low | |
| Radon | 1 | 0% | Low | Low ⓘ | |
| PFOS ⓘ municipal | 77 | 0% | Moderate | Safe | |
| PFOA ⓘ municipal | 77 | 0% | Moderate | Low | |
| HFPO-DA (GenX) ⓘ municipal | 77 | 0% | Moderate | Safe | |
| Sodium | 339 | — | High | Low | |
| pH | 222 | — | High | Low | |
| PFBS ⓘ municipal | 68 | — | Moderate | Safe | |
| Hardness | 142 | — | 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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