Well Water in Hidalgo County: What to Test and Why

Hidalgo County's groundwater contains arsenic, fluoride, iron, manganese, uranium, and PFOA and PFOS. Several of these contaminants exceed EPA health standards, making water testing important for well owners in this area.

The coastal lowlands geology here naturally releases these metals and elements into groundwater. The rock layers and soil contain uranium, arsenic, manganese, and iron that dissolve into water as it moves underground. Saltwater intrusion from the Gulf Coast also pushes additional minerals into the aquifer in some areas.

Groundwater in this county is notable for elevated iron and manganese from the natural rock layers below. As water passes through these materials over time, these metals dissolve into the water. Iron and manganese are common findings across wells throughout the county, though levels vary from well to well.

Wells in Hidalgo County contain several contaminants that exceed EPA health standards. Arsenic, uranium, and fluoride can damage organs and bones with long-term exposure. PFOA and PFOS are industrial chemicals linked to health problems including liver damage and weakened immunity. Manganese affects brain development in children. Iron and manganese do not pose direct health risks at the levels found here, but they are worth monitoring.

Iron in county wells causes orange or brown staining on fixtures, laundry, and dishes. Manganese leaves dark or black stains. Both minerals can create an unpleasant taste or metallic flavor in drinking water. These minerals also build up as scale inside pipes and appliances, though the water hardness here is moderate.

We recommend a comprehensive metals and minerals panel to find out what is actually in your well, since every well is different and yours may have higher or lower levels than what is common in the county. A comprehensive panel typically costs between $200 and $400. Testing is the only way to know exactly what you are dealing with so proper treatment can be selected. Reverse osmosis filters or activated carbon systems can address many of these concerns.