Groundwater in Darke County contains manganese, iron, arsenic, chloride, and other contaminants at levels that exceed EPA health standards. These exceedances mean your well water needs attention and testing.
The rock beneath Darke County naturally contains iron and manganese that dissolve into groundwater as water moves slowly through cracks and fractures in the stone. Arsenic is also trapped in these same rock layers and leaches into the water over time. Chloride and sulfate accumulate as groundwater sits in contact with mineral-rich stone.
Darke County groundwater is very hard, driven by dissolved calcium and magnesium from the limestone and shale layers below. The elevated iron adds to the mineral load of the water. These characteristics are widespread across wells throughout the county.
Wells in Darke County commonly contain arsenic, chloride, iron, manganese, PFOS, radon, and sulfate at levels above EPA health standards. Arsenic is toxic and builds up in your body over time, increasing the risk of cancer and organ damage. Radon is a radioactive gas that increases lung cancer risk when you breathe it in from contaminated water. Chloride at high levels can raise blood pressure. Manganese can harm brain development in children and affect nervous system function in adults.
The water in this county is extremely hard, which means you will see thick white crusty buildup on faucets, showerheads, and pipes. Iron causes orange-brown staining in sinks, toilets, and laundry. The combination of hardness and minerals may give the water a metallic or bitter taste. Over time, extremely hard water shortens the lifespan of water heaters, dishwashers, and other appliances.
We recommend testing your well with a comprehensive metals and minerals panel, since several contaminants exceed health standards. Every well is different, and your well 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. A comprehensive panel typically costs $200-400. Treatment options include whole-house systems combining water softening, arsenic removal, and radon aeration.
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 ⓘ |
|---|---|---|---|---|---|
| Manganese | 84 | 66% | 23% · 12% · 66% | Moderate | High |
| Iron | 95 | 62% | 28% · 10% · 61% | Moderate | High |
| Arsenic | 23 | 50% | 30% · 22% · 48% | Moderate | High |
| Radon | 4 | 25% | 50% · 25% · 25% | Low | High ⓘ |
| PFOS ⓘ municipal | 5 | 20% | 80% · 0% · 20% | Low | High ⓘ |
| Chloride | 66 | 15% | 71% · 14% · 15% | Moderate | High |
| Sulfate | 52 | 8% | 75% · 17% · 8% | Moderate | Moderate |
| Lead | 2 | 0% | 100% · 0% · 0% | Low | Low ⓘ |
| PFNA ⓘ municipal | 5 | 0% | 100% · 0% · 0% | Low | Safe ⓘ |
| PFOA ⓘ municipal | 5 | 0% | 100% · 0% · 0% | Low | Safe ⓘ |
| HFPO-DA (GenX) ⓘ municipal | 5 | 0% | 100% · 0% · 0% | Low | Safe ⓘ |
| Fluoride | 31 | 0% | 94% · 6% · 0% | Moderate | Low |
| Uranium | 5 | 0% | 100% · 0% · 0% | Low | Low ⓘ |
| PFHxS ⓘ municipal | 5 | 0% | 80% · 20% · 0% | Low | Low ⓘ |
| Hardness | 20 | — | — | Moderate | Low |
| Nitrite | 1 | 0% | 100% · 0% · 0% | Low | Safe ⓘ |
| E. coli | 1 | 0% | 100% · 0% · 0% | Low | Safe ⓘ |
| PFBS ⓘ municipal | 5 | — | 100% · 0% · 0% | Low | Safe ⓘ |
| pH | 6 | — | — | Low | Low ⓘ |
| Sodium | 32 | — | — | Moderate | Low |
| Nitrate | 1 | 0% | 100% · 0% · 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.
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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