Warren County groundwater contains arsenic, iron, lead, manganese, pfoa, pfos, and radon at levels that exceed EPA health standards. These are serious contaminants that require testing and treatment.
The rock beneath Warren County releases iron and manganese naturally as water moves through it. Arsenic, lead, pfoa, and pfos also come from the mixed bedrock geology. Radon forms from radioactive decay within the rock itself. This combination of fractured rock layers and low-oxygen conditions underground creates pathways for these contaminants to enter well water.
Groundwater in Warren County is very hard, driven by elevated calcium and magnesium from the limestone and other minerals in the rock below. The iron level is very high and contributes to the water's character. These hard-water and high-iron conditions are widespread across wells throughout the county.
Wells in Warren County commonly exceed EPA health standards for arsenic, lead, radon, and PFOA and PFOS. Arsenic and lead are toxic metals that build up in your body over time and can cause serious organ damage and cancer. Radon is a radioactive gas that increases lung cancer risk with long-term exposure. PFOA and PFOS are industrial chemicals linked to liver damage and other health problems.
The water in Warren County is extremely hard, which means you will see thick white crusty buildup on faucets and inside pipes. Iron levels are very high and will stain sinks, toilets, and laundry orange or rust-colored. Hard water this severe can shorten the lifespan of water heaters and dishwashers. The water may also taste metallic or slightly salty.
We recommend testing your well because every well is different and yours may 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. Since multiple contaminants exceed health standards, a comprehensive metals and minerals panel is recommended, which typically costs $200-$400. Treatment options include reverse osmosis systems combined with radon aeration or water softeners with iron filters.
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 | 115 | 61% | High | High | |
| Manganese | 102 | 55% | High | High | |
| PFOS ⓘ municipal | 32 | 28% | Moderate | High | |
| Arsenic | 104 | 25% | High | High | |
| Radon | 6 | 17% | Low | High ⓘ | |
| PFOA ⓘ municipal | 32 | 6% | Moderate | Moderate | |
| Lead | 99 | 1% | Moderate | Low | |
| Chloride | 118 | 0% | High | Low | |
| Fluoride | 57 | 0% | Moderate | Low | |
| HFPO-DA (GenX) ⓘ municipal | 32 | 0% | Moderate | Safe | |
| Nitrite | 22 | 0% | Moderate | Low | |
| PFHxS ⓘ municipal | 32 | 0% | Moderate | Low | |
| PFNA ⓘ municipal | 32 | 0% | Moderate | Safe | |
| Sulfate | 24 | 0% | Moderate | Low | |
| Uranium | 13 | 0% | Low | Low | |
| Nitrate | 39 | 0% | Moderate | Low | |
| E. coli | 2* | 0% | Low | Safe ⓘ | |
| Hardness | 100 | — | High | Low | |
| PFBS ⓘ municipal | 32 | — | Moderate | Low | |
| pH | 94 | — | Moderate | Low | |
| Sodium | 116 | — | High | Low | |
| Total Coliform | 2* | 0% | 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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