Williamson County groundwater contains radon, iron, fluoride, chloride, lead, manganese, nitrate, sulfate, and PFOA and PFOS chemicals. Several of these contaminants exceed EPA health standards and warrant attention.
These contaminants come from a mix of natural and human sources. Iron and manganese occur naturally when rainwater filters through the bedrock. Nitrate enters from fertilizers and septic systems. Chloride and sulfate build up from natural minerals in the rock. Lead can leach from old pipes or natural deposits. Radon seeps from uranium in the bedrock. PFOA and PFOS are industrial chemicals that have contaminated some areas through past disposal or manufacturing.
Groundwater in this county is very hard, driven by elevated calcium and magnesium from the limestone and other rock layers below. As rainwater moves through these rocks over time, it dissolves calcium and magnesium, which accumulate in the water. Very hard water is common across wells throughout this county.
Wells in Williamson County commonly contain several contaminants that exceed EPA health standards. Lead can harm brain development and learning in children. Nitrate poses risks to infants and can interfere with oxygen in the blood. Radon, a radioactive gas, increases lung cancer risk with long-term exposure. Fluoride, chloride, manganese, and PFOA and PFOS chemicals also appear at concerning levels in county wells.
The water in this county is very hard, which affects daily life. Hard water leaves white scale buildup inside pipes, water heaters, and dishwashers, and it can shorten the lifespan of these appliances. You may notice rust-colored stains on clothes and bathroom fixtures from iron. Soap does not work as well, and your skin or hair may feel dry after bathing.
We recommend testing your well with a comprehensive metals and minerals panel because county wells show multiple contaminants at elevated levels. Every well is different--your well might have higher or lower levels than what is common here. Testing is the only way to know what is actually in your water so you can treat it properly. Water softeners and iron filters can help address some of these concerns.
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 ⓘ |
|---|---|---|---|---|---|
| Radon | 3 | 67% | Low | High ⓘ | |
| Iron | 419 | 22% | High | High | |
| Fluoride | 1032 | 14% | High | Moderate | |
| Sulfate | 60 | 5% | Moderate | Moderate | |
| PFOS ⓘ municipal | 123 | 4% | High |
Moderate
Elevated concentration, not % above limit
|
|
| Nitrate | 102 | 3% | High | Low | |
| PFOA ⓘ municipal | 123 | 2% | High | Low | |
| Manganese | 354 | 2% | High | Low | |
| Lead | 137 | 2% | High | Low | |
| Chloride | 60 | 2% | Moderate | Low | |
| Arsenic | 131 | 0% | High | Low | |
| HFPO-DA (GenX) ⓘ municipal | 123 | 0% | High | Safe | |
| Nitrite | 54 | 0% | Moderate | Low | |
| PFHxS ⓘ municipal | 123 | 0% | High | Low | |
| PFNA ⓘ municipal | 123 | 0% | High | Low | |
| Uranium | 57 | 0% | Moderate | Low | |
| E. coli | 3* | 0% | Low | Low ⓘ | |
| Hardness | 61 | — | Moderate | Low | |
| PFBS ⓘ municipal | 123 | — | High | Low | |
| pH | 134 | — | High | Low | |
| Sodium | 61 | — | Moderate | Low | |
| Total Coliform | 3* | 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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