Groundwater in Dakota County contains arsenic, radon, and a group of human-made chemicals called PFOA, PFOS, PFHXS, and PFNA. Multiple of these contaminants exceed EPA health standards in this county's wells.
These contaminants come from different sources. Arsenic and radon occur naturally in the deep rock layers beneath the county. The PFOA, PFOS, PFHXS, and PFNA compounds come from industrial and consumer products used at the land surface--they enter groundwater through soil and migrate downward into the aquifer over time.
Groundwater in Dakota County is very hard, driven by calcium and magnesium dissolved from the rock layers below. As water moves slowly through the limestone and other minerals in the subsurface, it picks up these dissolved solids. Very hard water is common across wells in this county.
Wells in Dakota County commonly have arsenic, radioactive radon gas, and a group of chemicals called PFAS (including PFOA, PFOS, and PFHXS) at levels that exceed EPA health standards. Arsenic exposure can increase cancer risk and cause problems with the skin, heart, and nerves over time. Radon is a radioactive gas that gets into the lungs and increases the risk of lung cancer. PFAS chemicals build up in your body and can affect your immune system, liver, and thyroid.
The water in this county is very hard, which means it leaves white, chalky scale buildup on faucets, shower heads, and inside pipes. Hard water makes soap and shampoo less effective for cleaning and can leave spots on dishes and glassware. The mineral buildup can shorten the lifespan of water heaters, dishwashers, and washing machines. You may notice a slight metallic or mineral taste in the water.
Testing is the only way to know what is actually in your well, since every well is different and your water could have higher or lower levels than what is common in the county. We recommend a comprehensive water test that checks for metals, minerals, bacteria, nitrate, and PFAS, which typically costs between two hundred and four hundred dollars. Once you know what contaminants are present, you can install the right treatment system, such as activated carbon filters for PFAS or a radon vent system.
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 | |
| HFPO-DA (GenX) ⓘ municipal | 90 | 0% | Moderate | Safe | |
| Nitrite | 135 | 0% | High | Low | |
| Sulfate | 528 | 0% | High | Low | |
| Uranium | 37 | 0% | Moderate | Low | |
| Total Coliform | 8* | 0% | Low | Low ⓘ | |
| Sodium | 513 | — | High | Low | |
| pH | 493 | — | High | Low | |
| PFBS ⓘ municipal | 205 | — | 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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