Groundwater in this county contains E. coli and fecal coliform bacteria, along with HFPO-DA (a synthetic chemical from industrial use). The good news is that contaminant levels here are low and do not exceed EPA health standards.
Bacteria enter groundwater through cracks in well casings, nearby septic systems, or animal waste seeping down through soil. HFPO-DA comes from industrial or commercial sites where it was manufactured or used. The basin rock itself does not trap these contaminants--they arrive from the surface, which is why well construction and location matter for your water quality.
Based on the aquifer type here, groundwater in Orange County tends toward moderate hardness, with calcium and magnesium released as water flows through the Early Mesozoic basin rocks. These minerals dissolve naturally as groundwater sits in contact with the rock layers. Hardness levels vary across wells in this county depending on how long water spends underground and which rock layers it passes through.
Bacteria contamination is a concern in wells across Orange County. E. coli and fecal coliform in your well water can cause serious illness, including severe stomach cramps, diarrhea, and vomiting. These bacteria come from contamination and pose real health risks to you and your family. HFPO-DA is also present in some county wells and can affect your liver and immune system.
Mineral quality data for this county is limited, so we cannot describe specific aesthetic concerns like staining or scale at this time. Water quality varies greatly from well to well in Orange County.
We recommend testing your well right away. Every well is different, and your well may have higher or lower contamination levels than what is common in the county. Testing is the only way to know what is actually in your water so you can treat it properly. A basic bacterial screening costs around $50-100 and should be your first step. Disinfection systems or boiling can address bacterial contamination once it is detected.
| Contaminant | Samples ⓘ | % Above MCL ⓘ | Distribution ⓘ | Confidence ⓘ | Risk ⓘ |
|---|---|---|---|---|---|
| PFOS ⓘ municipal | 8 | 0% | Low | Safe ⓘ | |
| PFNA ⓘ municipal | 8 | 0% | Low | Safe ⓘ | |
| HFPO-DA (GenX) ⓘ municipal | 8 | 0% | Low | Safe ⓘ | |
| PFOA ⓘ municipal | 8 | 0% | Low | Safe ⓘ | |
| PFHxS ⓘ municipal | 8 | 0% | Low | Safe ⓘ | |
| PFBS ⓘ municipal | 8 | — | Low | Safe ⓘ |
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 →Loading recent water news…