Groundwater in Tompkins County contains manganese, radon, iron, arsenic, and chloride at levels that exceed EPA health standards. These contaminants are present at concentrations serious enough to warrant attention and testing.
Limestone bedrock beneath the county naturally releases manganese and iron as water dissolves through it over time. Radon seeps into groundwater from uranium decay in the rock. Arsenic and chloride can accumulate from the rock itself and from surface sources like road salt and agricultural activities.
Water in this county is hard, driven by calcium and magnesium from the limestone below. The carbonate rock dissolves slowly as groundwater moves through it, concentrating these minerals over time. Hard water with elevated iron and manganese is common across wells in this county.
Wells in Tompkins County commonly exceed EPA health standards for arsenic, chloride, iron, manganese, and radon. Arsenic can harm organs and increase cancer risk over time. Chloride at elevated levels can damage kidneys and raise blood pressure. Manganese affects brain and nervous system development, especially in children. Radon is a radioactive gas that increases lung cancer risk when breathed in over years. Iron and manganese also damage organs when consumed at high levels.
Hard water in county wells leaves white scale buildup inside pipes and on fixtures. Iron causes rust-colored or orange staining on sinks, toilets, and laundry. You may notice a metallic taste in the water. Hard water shortens the lifespan of water heaters, dishwashers, and other appliances by creating mineral deposits inside them.
We recommend a comprehensive metals and minerals panel to learn what is actually in your well, since every well is different and yours may have higher or lower levels than what is common here. Testing is the only way to know what needs treatment. A comprehensive panel typically costs two hundred to four hundred dollars. Depending on your results, treatment options like radon ventilation systems, water softeners, or whole-house filters can address specific problems.
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 | 107 | 69% | High | High | |
| Radon | 17 | 35% | Moderate | High ⓘ | |
| Iron | 105 | 24% | High | High | |
| Chloride | 126 | 4% | High |
Moderate
Elevated concentration, not % above limit
|
|
| Arsenic | 80 | 4% | Moderate |
Moderate
Elevated concentration, not % above limit
|
|
| Fluoride | 98 | 0% | Moderate | Low | |
| HFPO-DA (GenX) ⓘ municipal | 11 | 0% | Low | Safe | |
| Lead | 70 | 0% | Moderate | Low | |
| Nitrate | 101 | 0% | High | Low | |
| Nitrite | 74 | 0% | Moderate | Low | |
| PFHxS ⓘ municipal | 11 | 0% | Low | Safe | |
| PFNA ⓘ municipal | 11 | 0% | Low | Safe | |
| PFOA ⓘ municipal | 11 | 0% | Low | Safe | |
| PFOS ⓘ municipal | 11 | 0% | Low | Safe | |
| Sulfate | 125 | 0% | High | Low | |
| Uranium | 65 | 0% | Moderate | Low | |
| pH | 132 | — | High | Low | |
| Sodium | 106 | — | High | Low | |
| Total Coliform | 12* | 0% | Low | Low | |
| E. coli | 12* | 0% | Low | Safe | |
| Fecal Coliform | 12* | 0% | Low | Low | |
| Hardness | 125 | — | High | Low | |
| PFBS ⓘ municipal | 11 | — | 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.
* 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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