Groundwater in Polk County contains radon, arsenic, and chloride. Radon levels exceed the EPA health standard in this county, while arsenic and chloride are present at concentrations that do not exceed health standards.
Radon comes from natural decay of uranium in the crystalline bedrock beneath the county. Arsenic occurs naturally in the same rock. Chloride can come from both rock weathering and road salt used in winter, though levels here remain low.
Groundwater in Polk County is moderately hard, driven by calcium and magnesium released from the crystalline rock as water passes through it. The moderate hardness reflects the composition of the bedrock in this region. Most wells in the county show this same moderately hard character.
Radon is the main health concern in wells across Polk County. This radioactive gas comes from rock underground and can enter groundwater. Breathing radon vapor over time increases the risk of lung cancer. Arsenic and chloride are also present in some county wells at levels worth monitoring, as arsenic can cause serious health problems with long-term exposure.
The minerals in Polk County wells create moderate hardness, which means some households notice scale buildup on faucets and inside pipes. You might see white or cloudy deposits in showers or on dishes. The water in this county is not extremely hard, so appliance damage is not a major concern, but scale can still reduce water flow over time.
Testing your well is the only way to know what is actually in your water, since every well is different and your water may have higher or lower levels than the county average. We recommend a comprehensive testing panel that checks for radon, arsenic, and other metals and minerals--this typically costs between $200 and $400. A radon vent system or water treatment filters can address these concerns once you know your specific results.
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 ⓘ |
|---|---|---|---|---|---|
| Radon | 1 | 100% | Low | High ⓘ | |
| Arsenic | 1 | 0% | Low | Safe ⓘ | |
| Chloride | 1 | 0% | Low | Low ⓘ | |
| Fluoride | 1 | 0% | Low | Low ⓘ | |
| HFPO-DA (GenX) ⓘ municipal | 4 | 0% | Low | Safe ⓘ | |
| Iron | 1 | 0% | Low | Safe ⓘ | |
| Lead | 1 | 0% | Low | Low ⓘ | |
| Manganese | 1 | 0% | Low | Low ⓘ | |
| Nitrate | 1 | 0% | Low | Low ⓘ | |
| Nitrite | 1 | 0% | Low | Safe ⓘ | |
| PFHxS ⓘ municipal | 4 | 0% | Low | Safe ⓘ | |
| PFNA ⓘ municipal | 4 | 0% | Low | Safe ⓘ | |
| PFOA ⓘ municipal | 4 | 0% | Low | Safe ⓘ | |
| PFOS ⓘ municipal | 4 | 0% | Low | Safe ⓘ | |
| Sulfate | 1 | 0% | Low | Low ⓘ | |
| Uranium | 1 | 0% | Low | Low ⓘ | |
| Hardness | 1 | — | Low | Low ⓘ | |
| PFBS ⓘ municipal | 4 | — | Low | Safe ⓘ | |
| pH | 1 | — | Low | Low ⓘ | |
| Sodium | 1 | — | Low | 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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