Groundwater in Orange County contains manganese, iron, nitrate, and human-made chemicals called PFOA and PFOS. Several of these contaminants exceed EPA health standards at levels that warrant attention.
The crystalline rock beneath Orange County naturally releases manganese and iron as water passes through it over time. Nitrate enters groundwater from fertilizers and septic systems in developed areas. PFOA and PFOS come from industrial sources and contaminated sites; these chemicals don't break down easily and can spread through the water table.
Groundwater in this county is moderately hard, driven by calcium and magnesium released from the crystalline bedrock below. The rock's composition causes these minerals to dissolve into water moving through fractures and pores in the stone. Moderate hardness is a common condition across wells throughout Orange County.
Wells in Orange County often contain iron, manganese, nitrate, radon, and PFOA and PFOS at levels that exceed EPA health standards. Iron and manganese can harm your kidneys and nervous system over time. Nitrate is especially dangerous for infants and can interfere with how blood carries oxygen. Radon is a radioactive gas that increases lung cancer risk when you breathe it in. PFOA and PFOS are human-made chemicals that can affect your liver, immune system, and thyroid.
County wells have moderate hardness, which means you may notice some buildup of scale on faucets and fixtures, and soap may not lather as easily. Your water heater and dishwasher could wear out faster because of the mineral deposits that form inside them. The iron in some wells can create staining on sinks and laundry, though this varies from well to well.
Testing is the only way to know what is actually in your well. Since several contaminants exceed health standards in this county, we recommend a comprehensive metals and minerals panel along with testing for nitrate, radon, and PFOA and PFOS, which typically costs $200 to $400. Every well is different, so your well may have higher or lower levels than what is common countywide. Treatment options like activated carbon filters, radon ventilation systems, or reverse osmosis can address multiple contaminants depending on what testing reveals.
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 ⓘ |
|---|---|---|---|---|---|
| Manganese | 64 | 20% | Moderate | High | |
| PFOS ⓘ municipal | 17 | 18% | Moderate | High | |
| PFOA ⓘ municipal | 17 | 18% | Moderate | High | |
| Iron | 112 | 7% | High | Moderate | |
| Radon | 53 | 2% | Moderate | Low ⓘ | |
| Nitrate | 64 | 2% | Moderate | Low | |
| Arsenic | 33 | 0% | Moderate | Low | |
| Chloride | 112 | 0% | High | Low | |
| Fluoride | 112 | 0% | High | Low | |
| HFPO-DA (GenX) ⓘ municipal | 18 | 0% | Moderate | Safe | |
| Lead | 33 | 0% | Moderate | Low | |
| Nitrite | 53 | 0% | Moderate | Low | |
| PFHxS ⓘ municipal | 17 | 0% | Moderate | Safe | |
| PFNA ⓘ municipal | 18 | 0% | Moderate | Safe | |
| Sulfate | 112 | 0% | High | Low | |
| Uranium | 2 | 0% | Low | Low ⓘ | |
| Hardness | 112 | — | High | Low | |
| PFBS ⓘ municipal | 18 | — | Moderate | Safe | |
| pH | 113 | — | High | Low | |
| Sodium | 112 | — | 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.
Loading recent water news…