Well Water in Castro County: What to Test and Why

Groundwater in Castro County contains manganese, iron, arsenic, and fluoride at levels that exceed EPA health standards. These contaminants are present at concentrations high enough that well owners should take them seriously and consider testing their individual wells.

The High Plains aquifer here sits above and within rock layers that naturally contain iron and manganese minerals. As water moves slowly through these underground layers over many years, it dissolves these metals and carries them into wells. Arsenic and fluoride occur naturally in the same rock formations and leach into groundwater through the same process.

Groundwater in this county is very hard, driven mainly by high levels of calcium and magnesium dissolved from the rock layers below. The high mineral content reflects the chemistry of the underground formation itself--as water sits in contact with these rocks for long periods, it picks up dissolved minerals. Most wells in Castro County show this very hard water character, and elevated iron is also widespread across the area.

Wells in Castro County commonly have arsenic, fluoride, iron, and manganese at levels above EPA health standards. Arsenic can damage organs and increase cancer risk with long-term exposure. Fluoride at high levels can cause dental and skeletal problems. Iron and manganese can harm the brain and nervous system, especially in children and babies. These contaminants need attention because they build up in your body over time.

The very hard water in this county's wells will leave white scale on faucets and shower heads and can clog pipes. Hard water makes soap work poorly, so you'll use more shampoo and detergent. It can also shorten the life of water heaters, dishwashers, and washing machines. You might notice a metallic or bitter taste from the iron and manganese.

We recommend getting your well tested with a comprehensive panel that checks for metals and minerals, since several contaminants are present in county wells. Remember that your well is unique and could have much higher or lower levels than what is common here. Testing is the only way to know what is actually in your water so you can treat it properly. A comprehensive test runs between two hundred and four hundred dollars. Water softeners and filtration systems like carbon filters or reverse osmosis can help address these concerns.