Groundwater in Harris County contains arsenic, chloride, fluoride, iron, manganese, nitrate, radon, uranium, and PFOS and PFHXS compounds. Many of these contaminants exceed EPA health standards, making water testing and treatment important for well owners in this area.
The coastal lowlands aquifer system here naturally contains minerals and metals leached from underground rock and soil layers. Saltwater intrusion from the Gulf Coast adds chloride to wells closer to the shoreline. Industrial activity, farming, and urban development contribute nitrate and PFOS compounds to groundwater across the county.
Groundwater in Harris County is hard, driven by elevated calcium and magnesium, and also contains moderate levels of iron and sodium. These minerals dissolve naturally from the rock and clay layers that make up the coastal aquifer system. Hard water and elevated iron are found in wells throughout the county, though levels vary from well to well.
Wells in Harris County show several contaminants above EPA health standards. Arsenic, uranium, and radon can increase cancer risk over time. Nitrate threatens infants and can cause serious blood disorders. Fluoride at high levels harms bone and tooth development. PFOS and PFHXS are industrial chemicals linked to immune and liver problems. Manganese and iron at elevated levels affect the nervous system and organ function.
Hard water in county wells leaves scale buildup on fixtures and inside pipes. You'll notice staining from iron on sinks and clothes. The water may taste bitter or metallic. Hard water shortens the lifespan of water heaters and dishwashers. You could spend more on soap and detergent as they work less effectively.
We recommend a comprehensive water test since multiple contaminants exceed standards in this county. Every well is different--yours could have higher or lower levels than what is common here. Testing is the only way to know what is actually in your water so you can treat it correctly. A comprehensive panel costs between $200 and $400. Treatment options include reverse osmosis systems for many contaminants and water softeners for hardness.
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 | 79 | 56% | Moderate | High ⓘ | |
| Iron | 1522 | 13% | High | Moderate | |
| Manganese | 947 | 12% | High | Moderate | |
| PFOS ⓘ municipal | 1319 | 3% | High |
Moderate
Elevated concentration, not % above limit
|
|
| Arsenic | 661 | 3% | High | Low | |
| Nitrate | 216 | 2% | High | Low | |
| Uranium | 371 | 1% | High | Low | |
| Chloride | 1848 | 1% | High | Low | |
| Fluoride | 1567 | 1% | High | Low | |
| Sulfate | 628 | 0% | High | Low | |
| PFHxS ⓘ municipal | 1319 | 0% | High | Low | |
| HFPO-DA (GenX) ⓘ municipal | 1319 | 0% | High | Safe | |
| Lead | 458 | 0% | High | Low | |
| Nitrite | 139 | 0% | High | Low | |
| PFNA ⓘ municipal | 1319 | 0% | High | Safe | |
| PFOA ⓘ municipal | 1319 | 0% | High | Low | |
| Hardness | 390 | — | High | Low | |
| PFBS ⓘ municipal | 1319 | — | High | Low | |
| pH | 1851 | — | High | Low | |
| Sodium | 387 | — | 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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