Well Water in McLennan County: What to Test and Why

Groundwater in McLennan County contains radon, iron, arsenic, and several other contaminants that exceed EPA health standards including fluoride, manganese, and nitrate. These levels are serious enough that well owners should test their water and understand what is present in their supply.

The rock beneath this county naturally releases arsenic and fluoride into groundwater as water passes through. Radon comes from radioactive decay in the rock layer itself. Nitrate enters from fertilizer and septic systems in the soil above. Iron and manganese dissolve from the rocks as slightly acidic groundwater moves through them.

Groundwater in this county is soft overall but contains very high sodium and high sulfate that give the water a distinct mineral character. These salts dissolve naturally as water flows through the local rock layers. Many wells across McLennan County show these elevated sodium and sulfate concentrations.

Wells in McLennan County commonly exceed EPA health standards for arsenic, fluoride, nitrate, radon, iron, and manganese. Arsenic exposure over time can harm the kidneys and increase cancer risk. Fluoride at elevated levels can damage tooth enamel in children. Nitrate is especially dangerous for infants and can interfere with how blood carries oxygen. Radon is a radioactive gas that increases lung cancer risk when breathed in over years. Manganese and iron at high levels can affect the nervous system and organ function.

The high sodium levels in county wells can leave a salty taste in drinking water and may concern people on salt-restricted diets. Iron and manganese create orange or brown staining on fixtures, laundry, and dishes. You may notice a metallic or unpleasant taste and smell from these minerals. Although the water is relatively soft overall, these mineral issues affect daily quality of life.

Every well in McLennan County is different, and your well 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. We recommend a comprehensive metals and minerals panel that covers arsenic, fluoride, radon, and the mineral concerns present here. Treatment options like reverse osmosis systems, activated carbon filters, or ion exchange can address multiple contaminants depending on your results.