Groundwater in Gray County contains fluoride, iron, manganese, and nitrate at levels that exceed EPA health standards. These contaminants are present at concerning concentrations that well owners should address.
The High Plains aquifer underlying this county naturally contains these metals and minerals from the rock layers below. Nitrate comes from agricultural activities and septic systems that leach into the groundwater, while fluoride, iron, and manganese occur naturally as water moves through the soil and rock.
Groundwater in this county is very hard, driven by elevated calcium and magnesium dissolved from the rock, and also contains high sodium and moderate sulfate. The High Plains aquifer's geology concentrates these minerals as water filters down through layered sediments and bedrock over time. These characteristics are widespread across wells throughout Gray County.
Wells in Gray County commonly have fluoride, iron, manganese, and nitrate at levels above EPA health standards. Fluoride exposure in children during tooth development can cause dental fluorosis, which creates white spots or streaks on teeth. High nitrate levels are especially dangerous for infants and can interfere with oxygen in the blood. Manganese and iron at elevated levels can affect the nervous system and organs with long-term exposure.
The very hard water in this county creates real challenges for daily life. You will see stubborn scale buildup on faucets, shower heads, and inside pipes. Hard water reduces soap effectiveness, leaving spots on dishes and a sticky feeling on skin and hair. The high sodium content adds a salty taste to the water. Very hard water also shortens the lifespan of water heaters, dishwashers, and other appliances.
We recommend a comprehensive water test for your well since multiple contaminants exceed health standards in the 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 exactly what is in your well so you can treat it properly. A comprehensive panel typically costs between 200 and 400 dollars and will identify what filtration or other treatment your household needs.
| Contaminant | Samples ⓘ | % Above MCL ⓘ | Distribution ⓘ | Confidence ⓘ | Risk ⓘ |
|---|---|---|---|---|---|
| Iron | 124 | 5% | High |
Moderate
Elevated concentration, not % above limit
|
|
| Nitrate | 30 | 3% | Moderate |
Moderate
Elevated concentration, not % above limit
|
|
| Manganese | 119 | 3% | High | Low | |
| Fluoride | 713 | 0% | High | Low | |
| Arsenic | 119 | 0% | High | Low | |
| Chloride | 8 | 0% | Low | Low ⓘ | |
| HFPO-DA (GenX) ⓘ municipal | 10 | 0% | Low | Safe | |
| Lead | 116 | 0% | High | Low | |
| Nitrite | 8 | 0% | Low | Safe ⓘ | |
| PFHxS ⓘ municipal | 10 | 0% | Low | Safe | |
| PFNA ⓘ municipal | 10 | 0% | Low | Safe | |
| PFOA ⓘ municipal | 10 | 0% | Low | Safe | |
| PFOS ⓘ municipal | 10 | 0% | Low | Safe | |
| Radon | 4 | 0% | Low | Low ⓘ | |
| Sulfate | 8 | 0% | Low | Low ⓘ | |
| Uranium | 39 | 0% | Moderate | Low | |
| E. coli | 1* | 0% | Low | Low ⓘ | |
| Hardness | 8 | — | Low | Low ⓘ | |
| PFBS ⓘ municipal | 10 | — | Low | Safe | |
| pH | 8 | — | Low | Low ⓘ | |
| Sodium | 8 | — | Low | Low ⓘ | |
| Total Coliform | 1* | 0% | 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 →Population-level CDC data. Not individual risk prediction.
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