Groundwater in Jefferson County contains manganese, iron, chloride, arsenic, and nitrate. Several of these reach levels that exceed federal health standards, so well owners should have their water tested and treated if needed.
These contaminants come from the coastal geology beneath the county. The underground layers here contain minerals that dissolve into groundwater, and salt water from the nearby coast can move inland and raise chloride levels. Old industrial and agricultural activity in the area has also added nitrate to some wells.
Groundwater in this county is very hard, driven by elevated sodium and moderate iron. The coastal plain rock naturally releases these minerals as water moves through it over time. Hard, iron-bearing water is common across wells in Jefferson County, though levels vary from well to well.
Wells in Jefferson County commonly have arsenic, chloride, iron, manganese, and nitrate at levels above EPA health standards. Arsenic can damage your kidneys and increase cancer risk over many years of drinking. Manganese and nitrate can affect your nervous system and blood oxygen levels, especially in children and babies. Iron and chloride at high levels also pose health concerns for long-term exposure.
The very hard water in county wells causes stubborn staining on sinks and showers from iron and manganese buildup. You will likely see rust-colored or brown spots on laundry and fixtures. The water may taste salty from high sodium levels. Very hard water also shortens the lifespan of water heaters, dishwashers, and other appliances by creating scale deposits inside them.
We recommend testing your well water with a comprehensive panel since multiple analytes exceed health standards in this county. 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 metals and minerals panel typically costs between $200 and $400. Treatment options like reverse osmosis systems or ion exchange softeners can address these concerns once you know your specific levels.
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 | 62 | 47% | Moderate | High | |
| Chloride | 276 | 47% | High | High | |
| Iron | 109 | 32% | High | High | |
| Nitrate | 88 | 8% | Moderate | Moderate | |
| Arsenic | 60 | 3% | Moderate |
Moderate
Elevated concentration, not % above limit
|
|
| Sulfate | 226 | 3% | High | Low | |
| Fluoride | 255 | 0% | High | Low | |
| HFPO-DA (GenX) ⓘ municipal | 31 | 0% | Moderate | Safe | |
| Lead | 59 | 0% | Moderate | Low | |
| Nitrite | 5 | 0% | Low | Safe ⓘ | |
| PFHxS ⓘ municipal | 30 | 0% | Moderate | Safe | |
| PFNA ⓘ municipal | 30 | 0% | Moderate | Safe | |
| PFOA ⓘ municipal | 30 | 0% | Moderate | Safe | |
| PFOS ⓘ municipal | 30 | 0% | Moderate | Safe | |
| Radon | 4 | 0% | Low | Low ⓘ | |
| Uranium | 19 | 0% | Moderate | Safe | |
| Sodium | 110 | — | High | Low | |
| pH | 76 | — | Moderate | Low | |
| PFBS ⓘ municipal | 30 | — | Moderate | Safe | |
| Hardness | 241 | — | 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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