Groundwater in Frio County contains iron, manganese, chloride, fluoride, nitrate, and sulfate. Several of these contaminants exceed EPA health standards, making them a real concern for well owners in this area.
The rocks beneath Frio County naturally contain iron and manganese that dissolve into groundwater as water moves through the ground. Chloride and sulfate also occur naturally in these rocks and accumulate over time. Nitrate can come from both natural sources in the soil and from human activities like agriculture and septic systems in this rural area.
Groundwater in Frio County is very hard, driven by elevated calcium and magnesium that come from the rock layers below. The same rock formations that create hardness also contribute sulfate and other minerals to the water. These mineral characteristics are widespread across wells throughout the county due to the consistent geology beneath the area.
Wells in Frio County commonly have several substances at levels above EPA health standards. Nitrate can harm infants and interfere with how blood carries oxygen. Fluoride at elevated levels can cause dental problems and bone issues. Chloride and sulfate at high levels can upset your stomach and have laxative effects. Iron and manganese aren't direct health hazards at these levels, but they do indicate minerals in the water.
County wells tend to be very hard, which means lots of minerals dissolved in the water. You'll see white scale buildup in your pipes, faucets, and shower heads. Soap won't lather well, and your hair and skin may feel sticky. The water might have a metallic or salty taste. Hard water also shortens the life of water heaters, dishwashers, and washing machines because scale clogs them up.
We recommend testing your well with a comprehensive panel since multiple substances exceed standards in county wells. Your well's water is different from your neighbor's, and you need to know exactly what you have before deciding on treatment. Testing costs between two hundred and four hundred dollars for a full metals and minerals panel. Water softeners and iron filters are common solutions for these mineral 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 ⓘ |
|---|---|---|---|---|---|
| Iron | 326 | 56% | High | High | |
| Manganese | 223 | 20% | High | High | |
| Chloride | 73 | 19% | Moderate | High | |
| Sulfate | 71 | 17% | Moderate | High | |
| Nitrate | 109 | 5% | High |
Moderate
Elevated concentration, not % above limit
|
|
| Fluoride | 511 | 0% | High | Low | |
| Arsenic | 170 | 0% | High | Low | |
| HFPO-DA (GenX) ⓘ municipal | 12 | 0% | Low | Safe | |
| Lead | 170 | 0% | High | Low | |
| Nitrite | 2 | 0% | Low | Safe ⓘ | |
| PFHxS ⓘ municipal | 12 | 0% | Low | Safe | |
| PFNA ⓘ municipal | 12 | 0% | Low | Safe | |
| PFOA ⓘ municipal | 12 | 0% | Low | Safe | |
| PFOS ⓘ municipal | 12 | 0% | Low | Safe | |
| Radon | 2 | 0% | Low | Low ⓘ | |
| Uranium | 51 | 0% | Moderate | Low | |
| Hardness | 70 | — | Moderate | Low | |
| PFBS ⓘ municipal | 12 | — | Low | Safe | |
| pH | 57 | — | Moderate | Low | |
| Sodium | 70 | — | 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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