Webb County groundwater contains radon, chloride, and sulfate as the top detected contaminants. Several contaminants exceed EPA health standards at concerning levels, including arsenic, fluoride, uranium, lead, and manganese.
The rock layers in the Texas coastal uplands here naturally contain radioactive minerals that release radon, and they hold salt minerals like chloride and sulfate that dissolve into the water over time. As groundwater moves slowly through these rock formations, it picks up these dissolved minerals and radioactive elements.
Groundwater in this county is soft but notably high in sodium and sulfate. The coastal uplands rock naturally concentrates these salt minerals in the water as it flows underground. These characteristics are widespread across wells throughout the county.
County wells contain arsenic, uranium, lead, and radon at levels above EPA health standards. Arsenic and uranium damage organs over time and increase cancer risk. Lead harms brain development in children and raises blood pressure in adults. Radon is a radioactive gas that increases lung cancer risk when breathed in.
Water in this county has very high sodium and sulfate. High sodium can taste salty and is a concern for people watching their salt intake. Sulfate can give water a rotten egg smell and upset your stomach. The water is soft, so it won't leave mineral scale in pipes, but the salty taste and odor from these minerals will affect everyday use.
Your well is different from others in the county. Your water could have higher or lower levels of these contaminants. We recommend a comprehensive metals and minerals panel to see what is actually in your water--this typically costs $200-400. Once you know what you are dealing with, treatment options like reverse osmosis or activated carbon filters can remove or reduce these contaminants.
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 | 1 | 100% | Low | High ⓘ | |
| Chloride | 37 | 68% | Moderate | High | |
| Sulfate | 37 | 65% | Moderate | High | |
| Arsenic | 203 | 14% | High | Moderate | |
| Iron | 181 | 14% | High | Moderate | |
| Manganese | 173 | 9% | High | Moderate | |
| Uranium | 71 | 7% | Moderate | Moderate | |
| Fluoride | 271 | 2% | High | Low | |
| Lead | 164 | 1% | High | Low | |
| HFPO-DA (GenX) ⓘ municipal | 12 | 0% | Low | Safe | |
| Nitrate | 72 | 0% | Moderate | Low | |
| Nitrite | 36 | 0% | Moderate | Low | |
| PFHxS ⓘ municipal | 12 | 0% | Low | Safe | |
| PFNA ⓘ municipal | 12 | 0% | Low | Safe | |
| PFOA ⓘ municipal | 12 | 0% | Low | Safe | |
| PFOS ⓘ municipal | 12 | 0% | Low | Safe | |
| Sodium | 37 | — | Moderate | Low | |
| pH | 37 | — | Moderate | Low | |
| PFBS ⓘ municipal | 12 | — | Low | Safe | |
| Hardness | 37 | — | 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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