Well Water in Dunn County: What to Test and Why

Groundwater in Dunn County contains radon, iron, and arsenic. Iron and radon exceed EPA health standards and deserve attention, while arsenic is also present.

These contaminants come from the deep rock layers underneath the county. Water moving slowly through limestone and sandstone dissolves iron and picks up radon gas released by natural radioactive decay in the rock. Arsenic occurs naturally in these same rock formations.

Groundwater in this county is moderately hard, driven by iron at elevated levels. The deep bedrock naturally contains iron minerals that dissolve into water as it moves through the rock layers. Iron appears in most wells across the county at similar levels, making it a widespread characteristic of the water here.

Wells in Dunn County commonly exceed EPA health standards for iron and radon. Iron in drinking water does not pose direct health risks at the levels found here, but radon is a radioactive gas that can accumulate in your home and increase lung cancer risk over time with long-term exposure. Arsenic also appears in some county wells at levels worth monitoring, as it can increase cancer risk with repeated exposure over many years.

Iron in county well water leaves reddish or brownish stains on laundry, sinks, and fixtures. The water is moderately hard, which means you may notice white scale buildup on pipes and fixtures over time. Hard water can also shorten the lifespan of water heaters and dishwashers. Sodium and sulfate levels stay low in this county, so those are not concerns.

We recommend testing your well with a comprehensive metals and minerals panel, which typically costs between $200 and $400. 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. Iron removal systems and radon aeration treatment are effective options if testing shows elevated levels.