Groundwater in Orange County contains chloride, iron, manganese, PFOA, PFOS, and radon at levels that exceed EPA health standards. These contaminants are serious concerns that require testing and treatment.
The limestone rock beneath Orange County naturally releases iron and manganese as slightly acidic rainwater dissolves through it, while radon seeps from radioactive material in the bedrock. Road salt applied to county roads and highways enters groundwater as chloride. PFOA and PFOS come from industrial use and contaminated sites that have leaked these chemicals into the water supply.
Groundwater in this county is moderately hard, driven primarily by calcium and magnesium from the carbonate rock below. As water moves slowly through limestone, it dissolves these minerals and carries them into wells. These characteristics are widespread across wells throughout the county.
Wells in Orange County commonly have chloride, iron, manganese, PFOA, PFOS, and radon at levels exceeding EPA health standards. Radon is a radioactive gas that increases lung cancer risk over time when breathed in through water vapor. PFOA and PFOS are industrial chemicals linked to serious health problems including kidney and liver damage. Chloride at high levels can harm people with certain health conditions. Manganese can affect nervous system development in children and damage the brain over time.
Hard water in this county can shorten the lifespan of water heaters and dishwashers. You might notice reddish-brown staining from iron on fixtures and in sinks, along with a metallic taste in the water. Scale buildup can form on pipes and inside appliances, reducing their efficiency and making them work harder.
We recommend getting a comprehensive water test to find out exactly what is in your well, since 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 what needs treatment. A comprehensive metals and minerals panel typically costs $200 to $400. Depending on your results, treatment options like aeration systems and activated carbon filters can address multiple concerns.
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 | 128 | 52% | High | High | |
| Radon | 25 | 32% | Moderate | High ⓘ | |
| Iron | 216 | 15% | High | Moderate | |
| PFOA ⓘ municipal | 118 | 11% | High | Moderate | |
| PFOS ⓘ municipal | 118 | 3% | High |
Moderate
Elevated concentration, not % above limit
|
|
| Chloride | 224 | 2% | High | Low | |
| Arsenic | 53 | 0% | Moderate | Low | |
| Fluoride | 158 | 0% | High | Low | |
| HFPO-DA (GenX) ⓘ municipal | 118 | 0% | High | Safe | |
| Lead | 116 | 0% | High | Low | |
| Nitrate | 218 | 0% | High | Low | |
| Nitrite | 35 | 0% | Moderate | Low | |
| PFHxS ⓘ municipal | 118 | 0% | High | Low | |
| PFNA ⓘ municipal | 118 | 0% | High | Safe | |
| Sulfate | 224 | 0% | High | Low | |
| Uranium | 16 | 0% | Moderate | Low | |
| E. coli | 4* | 0% | Low | Low ⓘ | |
| Fecal Coliform | 4* | 0% | Low | Low ⓘ | |
| Hardness | 221 | — | High | Low | |
| PFBS ⓘ municipal | 118 | — | High | Low | |
| pH | 227 | — | High | Low | |
| Sodium | 133 | — | High | Low | |
| Total Coliform | 4* | 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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