Groundwater in Matagorda County contains arsenic, chloride, fluoride, iron, lead, manganese, nitrate, and radon at levels that exceed EPA health standards. These contaminants are present at concentrations serious enough that well owners should test their water and consider treatment options.
The coastal lowlands where this county sits receive saltwater intrusion from the Gulf of Mexico, which pushes chloride and other minerals into the aquifer. Radon seeps from natural radioactive decay in rocks below. Iron and manganese dissolve from the sediments in this low-lying aquifer system. Arsenic, fluoride, lead, and nitrate come from a mix of natural geology and human activities like farming and industrial use in the area.
Groundwater in Matagorda County is very hard, driven by elevated calcium and magnesium from minerals in the coastal sediments. Sodium is also high here because of saltwater influence moving inland. These mineral-rich conditions are widespread across the county's wells, reflecting the coastal aquifer's natural chemistry and its proximity to the Gulf.
Wells in Matagorda County commonly contain arsenic, lead, nitrate, radon, and manganese at levels above EPA health standards. Arsenic and lead are serious concerns because they can damage your kidneys and nervous system, especially in children. Radon is a radioactive gas that increases lung cancer risk when you breathe it in over time. Nitrate and manganese can affect your blood and nervous system as well.
The water in this county is very hard, which causes scale buildup on fixtures and inside pipes and water heaters. Hard water can shorten the life of appliances like dishwashers and water heaters. You may also notice rust stains from iron in the water, spots on dishes and glassware, and a metallic taste. The high sodium content means the water tastes salty to some people.
We recommend testing your well with a comprehensive panel that checks for metals, bacteria, and minerals. Every well is different, and your water could have higher or lower levels than what is common here. Testing is the only way to know what is actually in your well so you can treat it properly. A comprehensive panel typically costs between $200 and $400, and treatment options include filtration systems, water softeners, and radon removal depending on what testing shows.
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 ⓘ | |
| Manganese | 483 | 38% | High | High | |
| Chloride | 252 | 21% | High | High | |
| Iron | 438 | 16% | High | High | |
| Arsenic | 191 | 2% | High | Low | |
| Nitrate | 247 | 1% | High | Low | |
| Lead | 185 | 1% | High | Low | |
| Fluoride | 845 | 0% | High | Low | |
| HFPO-DA (GenX) ⓘ municipal | 13 | 0% | Low | Safe | |
| Nitrite | 1 | 0% | Low | Low ⓘ | |
| PFHxS ⓘ municipal | 13 | 0% | Low | Safe | |
| PFNA ⓘ municipal | 13 | 0% | Low | Safe | |
| PFOA ⓘ municipal | 13 | 0% | Low | Safe | |
| PFOS ⓘ municipal | 13 | 0% | Low | Safe | |
| Sulfate | 248 | 0% | High | Low | |
| Uranium | 84 | 0% | Moderate | Low | |
| Sodium | 250 | — | High | Low | |
| pH | 241 | — | High | Low | |
| PFBS ⓘ municipal | 13 | — | Low | Safe | |
| Hardness | 248 | — | 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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