Groundwater in Delaware County contains PFOA, radon, manganese, and several other contaminants that exceed EPA health standards, including chloride, iron, nitrate, and PFOS. These levels are serious enough to warrant testing and potential treatment.
The Northern Atlantic Coastal Plain aquifer system here has mixed layers of sand, gravel, and clay that allow water to move relatively freely and pick up contaminants. PFOA and PFOS come from industrial use and manufacturing sites. Radon seeps naturally from uranium present in the rock. Manganese, iron, nitrate, and chloride dissolve from minerals in the ground or enter from road salt, septic systems, and fertilizer runoff in this area with significant development and aging infrastructure.
Groundwater in this county is moderately hard, driven by moderate levels of iron and moderate hardness overall. Iron dissolves naturally from minerals in the sandy and gravelly layers that make up the aquifer system here. These characteristics show up in a substantial portion of wells tested across the county.
Wells in Delaware County commonly exceed EPA health standards for radon, nitrate, chloride, iron, manganese, and PFOA and PFOS. Radon is a radioactive gas that increases cancer risk when breathed in over time. Nitrate harms infants and can reduce the blood's ability to carry oxygen. PFOA and PFOS are industrial chemicals linked to thyroid disease and other health concerns. Manganese exposure can affect brain development and the nervous system. Iron and chloride, while primarily aesthetic concerns, can also pose health risks at very high levels.
Wells in this county show moderate hardness, which causes white crusty scale buildup on fixtures and in pipes. Iron staining appears as rust-colored marks on sinks, toilets, and laundry. Hard water also reduces how well soap lathers and can shorten the lifespan of water heaters and dishwashers over time. Some residents notice a metallic or slightly salty taste in their water.
We recommend testing your well with a comprehensive metals and minerals panel, since multiple contaminants exceed health standards in county wells. Every well is different, and your well may have higher or lower levels than what is common here. 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. Treatment options include activated carbon filters for PFOA and PFOS removal, combined with aeration or whole-house filtration systems for metals.
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 ⓘ |
|---|---|---|---|---|---|
| PFOA ⓘ municipal | 54 | 72% | Moderate | High | |
| Radon | 5 | 60% | Low | High ⓘ | |
| Manganese | 35 | 31% | Moderate | High | |
| Iron | 42 | 31% | Moderate | High | |
| PFOS ⓘ municipal | 54 | 15% | Moderate | Moderate | |
| Chloride | 50 | 8% | Moderate | Moderate | |
| Nitrate | 49 | 2% | Moderate | Low | |
| Fluoride | 35 | 0% | Moderate | Low | |
| HFPO-DA (GenX) ⓘ municipal | 54 | 0% | Moderate | Safe | |
| Nitrite | 33 | 0% | Moderate | Low | |
| Lead | 26 | 0% | Moderate | Low | |
| Arsenic | 33 | 0% | Moderate | Low | |
| PFHxS ⓘ municipal | 20 | 0% | Moderate | Safe | |
| PFNA ⓘ municipal | 20 | 0% | Moderate | Low | |
| Sulfate | 42 | 0% | Moderate | Low | |
| Hardness | 42 | — | Moderate | Low | |
| PFBS ⓘ municipal | 54 | — | Moderate | Low | |
| pH | 54 | — | Moderate | Low | |
| Sodium | 40 | — | 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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