Groundwater in Warren County contains iron, radon, nitrate, and pfos. Iron and radon exceed EPA health standards, while nitrate and pfos also appear at levels of concern.
Iron comes naturally from the crystalline rock beneath Warren County as groundwater flows through cracks and dissolves minerals. Radon seeps in from radioactive elements in that same rock. Nitrate enters from septic systems and fertilizer use on the land above. Pfos is a human-made chemical from industrial sources and some firefighting foams that has contaminated groundwater in scattered locations.
Groundwater in this county is soft, with moderate iron being the main mineral character. The crystalline rock here does not contain much calcium or magnesium, which is why the water stays soft. Iron concentration comes directly from the bedrock minerals as water filters slowly through cracks and fissures. Moderate iron elevation shows up in many wells across the county.
Wells in Warren County commonly contain iron, nitrate, PFOS, and radon at levels that exceed EPA health standards. Iron can affect the kidneys and liver with long-term exposure. Nitrate poses a particular risk to infants and pregnant women, potentially affecting oxygen in the blood. PFOS is a human-made chemical linked to immune system and liver effects. Radon is a radioactive gas that enters through cracks in foundations and increases lung cancer risk over time.
The moderate iron levels in county wells create visible orange or brown staining on fixtures, laundry, and surfaces that can be difficult to clean. You may notice a metallic taste or odor in the water. The good news is that wells in this county are soft, so you won't experience the scale buildup or shortened appliance lifespan that comes with hard water.
We recommend a comprehensive testing panel since multiple contaminants exceed health standards in this county. Every well is different, and your well may have higher or lower levels than what's common here. Testing is the only way to know what's actually in your water so it can be properly treated. A comprehensive metals and PFOS panel typically costs $200 to $400. Treatment options like activated carbon filters or specialized systems can address these contaminants.
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 | 4 | 75% | Low | High ⓘ | |
| Radon | 2 | 50% | Low | High ⓘ | |
| Iron | 18 | 22% | Moderate | High | |
| Nitrate | 18 | 6% | Moderate | Moderate | |
| Arsenic | 2 | 0% | Low | Low ⓘ | |
| Chloride | 18 | 0% | Moderate | Low | |
| Fluoride | 18 | 0% | Moderate | Low | |
| HFPO-DA (GenX) ⓘ municipal | 4 | 0% | Low | Safe ⓘ | |
| Lead | 2 | 0% | Low | Low ⓘ | |
| Manganese | 18 | 0% | Moderate | Low | |
| Nitrite | 2 | 0% | Low | Low ⓘ | |
| PFHxS ⓘ municipal | 4 | 0% | Low | Safe ⓘ | |
| PFNA ⓘ municipal | 4 | 0% | Low | Safe ⓘ | |
| PFOA ⓘ municipal | 4 | 0% | Low | Safe ⓘ | |
| Sulfate | 18 | 0% | Moderate | Low | |
| Uranium | 2 | 0% | Low | Low ⓘ | |
| Hardness | 18 | — | Moderate | Low | |
| PFBS ⓘ municipal | 4 | — | Low | Safe ⓘ | |
| pH | 18 | — | Moderate | Low | |
| Sodium | 18 | — | 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.
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