Groundwater in Dakota County contains pfos, pfoa, and pfhxs along with arsenic, chloride, iron, lead, manganese, nitrate, and radon. Several of these contaminants exceed EPA health standards and warrant your attention.
These contaminants come from mixed sources rooted in the county's geology and human activity. The deep bedrock here naturally contains arsenic, iron, manganese, and radon that dissolve into water as it moves slowly underground. Nitrate and chloride enter from fertilizer, septic systems, and road salt applied on the land surface. The pfas chemicals--pfos, pfoa, and pfhxs--come from industrial use and contaminated sites that have leaked into groundwater over time.
Groundwater in Dakota County is very hard, driven by elevated calcium and magnesium from minerals in the bedrock below. Iron also appears at high levels as the deep rock releases it into the water. These mineral characteristics show up across most wells in the county, though individual wells can vary in exactly what they contain.
Wells in Dakota County commonly exceed EPA health standards for arsenic, lead, nitrate, radon, and several PFAS chemicals like PFOA and PFOS. Arsenic and lead can damage organs and increase cancer risk. Nitrate is especially harmful to infants and young children. Radon is a radioactive gas that enters through soil and rock. These contaminants pose real health concerns that warrant attention.
The county's water is very hard, which causes white scale buildup inside pipes and on fixtures. Iron at elevated levels creates rust-colored staining on laundry, dishes, and bathroom surfaces. Hard water shortens the lifespan of water heaters, dishwashers, and other appliances. You may notice a metallic taste or reduced effectiveness of soap and shampoo.
We recommend testing your well with a comprehensive metals, minerals, and PFAS panel since multiple contaminants exceed standards. Every well is different--yours could 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. A comprehensive panel typically costs $200-400 and can guide treatment options like ion exchange softeners, activated carbon filters, or radon removal systems.
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 ⓘ |
|---|---|---|---|---|---|
| PFOS ⓘ municipal | 376 | 70% | High | High | |
| PFOA ⓘ municipal | 317 | 68% | High | High | |
| PFHxS ⓘ municipal | 212 | 56% | High | High | |
| Iron | 489 | 38% | High | High | |
| Manganese | 451 | 38% | High | High | |
| Nitrate | 229 | 10% | High | Moderate | |
| PFNA ⓘ municipal | 195 | 8% | High | Moderate | |
| Radon | 13 | 8% | Low | Moderate ⓘ | |
| Arsenic | 365 | 3% | High | Low | |
| Chloride | 609 | 2% | High | Low | |
| Lead | 365 | 2% | High | Low | |
| Fluoride | 415 | 0% | High | Low | |
| Nitrite | 135 | 0% | High | Low | |
| Sulfate | 528 | 0% | High | Low | |
| Uranium | 37 | 0% | Moderate | Low | |
| HFPO-DA (GenX) ⓘ municipal | 90 | 0% | Moderate | Safe | |
| Total Coliform | 8* | 0% | Low | Low ⓘ | |
| Sodium | 513 | — | High | Low | |
| PFBS ⓘ municipal | 205 | — | High | Low | |
| pH | 493 | — | High | Low | |
| Hardness | 218 | — | High | Low | |
| E. coli | 8* | 0% | 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.
* 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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