Well Water in Hardin County: What to Test and Why

Groundwater in Hardin County contains arsenic, iron, and manganese at levels that exceed EPA health standards. Sulfate is also present at moderate levels, adding to the mineral load in the water.

These contaminants come from the bedrock itself--a layer of rock hundreds of millions of years old with tiny cracks and fractures. As groundwater moves slowly through these cracks, it dissolves iron, manganese, and arsenic locked inside the rock, along with sulfate from minerals naturally present in the stone.

Groundwater in Hardin County is very hard, driven by elevated calcium and magnesium from the limestone below, alongside high iron content. The slow contact between water and these mineral-rich rocks concentrates these elements as water seeps downward. These hard-water characteristics are widespread across wells throughout the county.

Arsenic, iron, manganese, and sulfate all exceed EPA health standards in wells across this county. Arsenic is colorless and odorless, so you cannot taste or smell it, but long-term exposure increases the risk of cancer and organ damage. Iron and manganese at elevated levels can affect brain development and organ function over time. Sulfate at high concentrations can cause digestive problems.

Wells in this county produce very hard water that leaves thick white, crusty scale on fixtures and inside pipes. The high iron content stains sinks, toilets, and laundry orange-brown and can give water a metallic taste. Water heaters, dishwashers, and other appliances wear out faster in extremely hard water like this.

We recommend testing your well because every well is different and yours 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 water so it can be properly treated. Since multiple analytes exceed standards here, a comprehensive mineral and metals panel is recommended and typically costs $200-400. Treatment options include a water softener paired with iron filtration and an arsenic-removal system.