Groundwater in Hays County contains arsenic, chloride, fluoride, iron, lead, manganese, nitrate, and sulfate at levels that exceed EPA health standards. These contaminants are present at concerning levels and well owners should have their water tested to understand what they are drinking.
The rock underneath Hays County naturally contains these metals and salts. As water moves through the ground over time, it dissolves these elements from the rock and picks them up. The local geology here makes it easy for these substances to end up in well water.
Groundwater in Hays County is very hard, driven by elevated calcium and magnesium from the rock below. The hard water comes from limestone and similar rock in the area that releases these minerals as water passes through. Very hard water is the normal condition across most wells in this county.
Wells in Hays County can contain arsenic, chloride, fluoride, iron, lead, manganese, nitrate, and sulfate at levels that exceed EPA health standards. Arsenic and lead are especially serious because they build up in your body over time and can cause nervous system damage, cancer, and organ problems. Nitrate is dangerous for infants and can prevent the blood from carrying oxygen properly. Manganese at high levels can harm the brain and nervous system.
The very hard water in county wells causes scale buildup on fixtures, faucets, and inside pipes. You may notice rust stains from iron on sinks and laundry. Hard water makes soap less effective and leaves spots on dishes. The mineral scale shortens the lifespan of water heaters, dishwashers, and other appliances. You might notice a metallic or sulfur taste in the water.
We recommend testing your well water with a comprehensive metals and minerals panel, which typically costs $200 to $400. Every well is different and yours could have higher or lower levels than what is common in the county. Testing is the only way to know exactly what is in your water so you can treat it properly. Water softeners can reduce hardness, and carbon filters or reverse osmosis systems can address some 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 ⓘ |
|---|---|---|---|---|---|
| Sulfate | 730 | 22% | High | High | |
| Chloride | 729 | 13% | High | Moderate | |
| Iron | 925 | 12% | High | Moderate | |
| Fluoride | 1554 | 6% | High | Moderate | |
| Manganese | 817 | 2% | High | Low | |
| Arsenic | 780 | 1% | High | Low | |
| Nitrate | 607 | 0% | High | Low | |
| Lead | 700 | 0% | High | Low | |
| HFPO-DA (GenX) ⓘ municipal | 101 | 0% | High | Safe | |
| Nitrite | 447 | 0% | High | Low | |
| PFHxS ⓘ municipal | 101 | 0% | High | Low | |
| PFNA ⓘ municipal | 101 | 0% | High | Safe | |
| PFOA ⓘ municipal | 101 | 0% | High | Safe | |
| PFOS ⓘ municipal | 101 | 0% | High | Safe | |
| Radon | 9 | 0% | Low | Low ⓘ | |
| Uranium | 383 | 0% | High | Low | |
| E. coli | 5* | 0% | Low | Low ⓘ | |
| Hardness | 700 | — | High | Low | |
| PFBS ⓘ municipal | 101 | — | High | Low | |
| pH | 768 | — | High | Low | |
| Sodium | 470 | — | High | Low | |
| Total Coliform | 5* | 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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