Groundwater in Nobles County contains arsenic, chloride, fluoride, iron, lead, manganese, nitrate, and sulfate at levels that exceed EPA health standards. Several of these contaminants reach high or very high concentrations, making testing and treatment important for your well.
These contaminants come from two main sources. The bedrock naturally releases arsenic, iron, manganese, and sulfate as water moves through it over time. Nitrate, chloride, and fluoride enter from human activities like farming, road salt, and septic systems, mixing with what the rock contributes.
Groundwater in this county is very hard and very high in iron and sulfate, driven by minerals dissolving from the bedrock as water passes through. The combination of limestone and shale layers in the underlying rock releases calcium, magnesium, iron, and sulfate into the water. These characteristics are widespread across wells throughout the county.
Wells in Nobles County show concerning levels of arsenic, lead, and nitrate that exceed EPA health standards. Arsenic can harm your kidneys, heart, and skin over time. Lead damages children's brain development and learning. Nitrate is especially dangerous for babies under six months old and can prevent oxygen from reaching their blood. Manganese at high levels can affect the nervous system and cause problems with movement and behavior.
The water in this county is extremely hard with very high iron and sulfate levels. You will see orange or brown staining on sinks, toilets, and laundry. Scale builds up inside pipes and water heaters, shortening their lifespan. The water may taste bitter or metallic, and soap won't lather well. Your dishwasher and water heater may wear out faster than normal.
Testing is the only way to know what is actually in your well so you can treat it properly. Your well could have higher or lower levels than what is common in the county. We recommend a comprehensive metals and minerals panel, which typically costs between two hundred and four hundred dollars. Treatment options like reverse osmosis systems or activated carbon filters can remove many of these contaminants.
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 | 125 | 85% | High | High | |
| Sulfate | 139 | 80% | High | High | |
| Iron | 140 | 69% | High | High | |
| Arsenic | 79 | 23% | Moderate | High | |
| Nitrate | 63 | 11% | Moderate | Moderate | |
| Lead | 79 | 4% | Moderate |
Moderate
Elevated concentration, not % above limit
|
|
| Fluoride | 120 | 1% | High | Low | |
| Chloride | 141 | 1% | High | Low | |
| PFNA ⓘ municipal | 5 | 0% | Low | Safe ⓘ | |
| PFOA ⓘ municipal | 5 | 0% | Low | Safe ⓘ | |
| PFOS ⓘ municipal | 5 | 0% | Low | Safe ⓘ | |
| HFPO-DA (GenX) ⓘ municipal | 5 | 0% | Low | Safe ⓘ | |
| Nitrite | 18 | 0% | Moderate | Low | |
| PFHxS ⓘ municipal | 5 | 0% | Low | Safe ⓘ | |
| Sodium | 132 | — | High | Low | |
| pH | 35 | — | Moderate | Low | |
| PFBS ⓘ municipal | 5 | — | Low | Safe ⓘ | |
| Hardness | 35 | — | 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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