Groundwater in Guadalupe County contains iron, manganese, nitrate, arsenic, chloride, fluoride, and sulfate. Several of these contaminants exceed EPA health standards, making them a concern for well owners.
The rock beneath this county naturally releases iron and manganese as water flows through it. Nitrate enters from fertilizers and septic systems used in farming and residential areas. Chloride and sulfate dissolve from the rock layers and can also seep up from deeper, saltier zones. Arsenic occurs naturally in the local geology.
This county's groundwater is very hard, with elevated calcium and magnesium from the limestone and other rock below. High sodium, sulfate, and iron also shape the water's character. These mineral concentrations are widespread across wells throughout the county.
Wells in Guadalupe County contain arsenic, chloride, fluoride, iron, manganese, nitrate, PFOS, and sulfate at levels that exceed EPA health standards. Arsenic can harm your kidneys and increase cancer risk over time. Nitrate is dangerous for infants and can interfere with how blood carries oxygen. Manganese and fluoride at high levels can damage your nervous system and teeth. PFOS is a chemical linked to health problems including liver damage and weakened immunity.
The water in this county is very hard, which causes white crusty scale buildup in pipes and on fixtures. Iron and manganese create orange, brown, and black staining on laundry, sinks, and toilets. You may notice a metallic or rotten egg taste and odor. Very hard water shortens the lifespan of water heaters, dishwashers, and other appliances because minerals clog and corrode them.
Since multiple contaminants exceed health standards in county wells, we recommend a comprehensive metals and minerals panel to find out what is actually in your well. Every well is different--yours could have higher or lower levels than what is common here. Testing is the only way to know what you need to treat. A comprehensive panel typically costs $200-400, and treatment options include reverse osmosis systems or specialized filters tailored to your results.
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 | 124 | 43% | High | High | |
| Nitrate | 100 | 33% | High | High | |
| Manganese | 26 | 27% | Moderate | High | |
| Chloride | 148 | 26% | High | High | |
| Sulfate | 123 | 18% | High | High | |
| Arsenic | 25 | 8% | Moderate | Moderate | |
| PFOS ⓘ municipal | 52 | 2% | Moderate | Low | |
| Fluoride | 206 | 1% | High | Low | |
| HFPO-DA (GenX) ⓘ municipal | 52 | 0% | Moderate | Safe | |
| Lead | 25 | 0% | Moderate | Low | |
| Nitrite | 8 | 0% | Low | Low ⓘ | |
| PFHxS ⓘ municipal | 52 | 0% | Moderate | Safe | |
| PFNA ⓘ municipal | 52 | 0% | Moderate | Safe | |
| PFOA ⓘ municipal | 52 | 0% | Moderate | Safe | |
| Radon | 3 | 0% | Low | Low ⓘ | |
| Uranium | 10 | 0% | Low | Low | |
| Hardness | 114 | — | High | Low | |
| PFBS ⓘ municipal | 52 | — | Moderate | Safe | |
| pH | 129 | — | High | Low | |
| Sodium | 114 | — | High | 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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