Well owners in Grand Isle County should be aware of chloride, fluoride, iron, lead, manganese, nitrate, and uranium in their groundwater. Several of these contaminants exceed EPA health standards and warrant attention.
These contaminants enter groundwater through a combination of natural and human sources. The limestone bedrock naturally contains some of these minerals, which dissolve as water moves through rock layers. Chloride and nitrate often come from road salt, fertilizers, and septic systems in this area. Lead and uranium can leach from rock and old pipes. The limestone geology here makes the water more able to hold onto dissolved minerals and contaminants.
Groundwater in this county is very hard, driven by calcium and magnesium from the limestone below, and it also carries notably high sodium. The limestone that supplies your well naturally dissolves and releases these minerals into the water as it filters down through the rock. High sodium levels are a particular feature of wells in this county and appear commonly across the region.
Wells in Grand Isle County contain several analytes at levels that exceed EPA health standards. Chloride, fluoride, lead, manganese, nitrate, and uranium are found in county groundwater. Lead damages the nervous system, especially in children, and can affect learning and behavior. Nitrate and uranium harm the kidneys and can increase cancer risk. Manganese affects the brain and nervous system development in children.
The water in this county is extremely hard, which means scale builds up inside pipes, water heaters, and dishwashers. This scale shortens the lifespan of appliances and reduces water flow. You might notice white crusty deposits on faucets and showerheads. High sodium in the water adds to the mineral taste and can be a concern for people on restricted diets.
We recommend testing your well water. Every well is different--your water may have higher or lower levels than what is common in the county. A comprehensive testing panel is the best choice given the multiple contaminants of concern, and it typically costs two hundred to four hundred dollars. Testing is the only way to know what is actually in your water so you can treat it properly. Water softeners, reverse osmosis systems, or point-of-use filters can help depending on what your test shows.
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 ⓘ |
|---|---|---|---|---|---|
| Iron | 125 | 33% | High | High | |
| Manganese | 143 | 14% | High | Moderate | |
| Chloride | 330 | 7% | High | Moderate | |
| Lead | 457 | 4% | High |
Moderate
Elevated concentration, not % above limit
|
|
| Nitrate | 445 | 0% | High | Low | |
| Uranium | 339 | 0% | High | Low | |
| Fluoride | 377 | 0% | High | Low | |
| Arsenic | 349 | 0% | High | Low | |
| Nitrite | 443 | 0% | High | Low | |
| Sodium | 133 | — | High | Low | |
| pH | 145 | — | High | Low | |
| Hardness | 84 | — | Moderate | 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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