Groundwater in Mackinac County contains iron, manganese, and lead that well owners should be aware of. Iron and lead exceed EPA health standards, while manganese also exceeds its limit, making these contaminants a notable concern.
These metals dissolve naturally from the bedrock that lies beneath the county. The Silurian and Devonian rock layers here contain iron minerals, and as groundwater moves slowly through cracks in the stone over time, these metals dissolve into the water. Lead can also seep in from old pipes and brass fittings in some wells.
Groundwater in this county is very hard, with elevated calcium and magnesium coming from the limestone and dolomite bedrock below. The slow movement of water through these mineral-rich rock layers concentrates these hardness minerals in the water. Very hard water is common across wells throughout Mackinac County.
Wells in Mackinac County commonly exceed EPA health standards for iron, lead, manganese, and sulfate. Iron exposure over time can damage your organs and affect how your body uses oxygen. Lead is especially dangerous because it harms brain development in children and can raise blood pressure in adults. Manganese at elevated levels can affect brain function and development. Sulfate at high levels can cause digestive problems in some people.
The water in this county is extremely hard, which causes white crusty buildup on pipes, faucets, and fixtures. Iron stains sinks, toilets, and laundry a rust-orange color that is difficult to remove. The water may taste metallic or have an unpleasant odor. Over time, the mineral buildup can shorten the lifespan of water heaters and dishwashers.
We recommend testing your well water through a certified lab, since every well is different and your water may have higher or lower levels than what is common in the county. Testing is the only way to know what is actually in your well so it can be properly treated. A comprehensive metals and minerals panel typically costs $200-400. Treatment options like iron filtration systems combined with water softeners can address multiple contaminants at once.
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 | 9 | 78% | Low | High ⓘ | |
| Manganese | 9 | 22% | Low | High ⓘ | |
| Sulfate | 9 | 11% | Low | Moderate ⓘ | |
| Lead | 9 | 11% | Low | Moderate ⓘ | |
| Nitrate | 9 | 0% | Low | Low ⓘ | |
| Arsenic | 9 | 0% | Low | Low ⓘ | |
| Chloride | 9 | 0% | Low | Low ⓘ | |
| Fluoride | 9 | 0% | Low | Low ⓘ | |
| HFPO-DA (GenX) ⓘ municipal | 2 | 0% | Low | Safe ⓘ | |
| Nitrite | 9 | 0% | Low | Safe ⓘ | |
| PFHxS ⓘ municipal | 2 | 0% | Low | Safe ⓘ | |
| PFNA ⓘ municipal | 2 | 0% | Low | Safe ⓘ | |
| PFOA ⓘ municipal | 12 | 0% | Low | Safe | |
| PFOS ⓘ municipal | 2 | 0% | Low | Safe ⓘ | |
| Uranium | 7 | 0% | Low | Low ⓘ | |
| Hardness | 9 | — | Low | Low ⓘ | |
| PFBS ⓘ municipal | 2 | — | Low | Safe ⓘ | |
| pH | 10 | — | Low | Low | |
| Sodium | 9 | — | 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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