Well Water in Fairfax County: What to Test and Why

Groundwater in Fairfax County contains iron, manganese, and per- and polyfluoroalkyl substances (PFOA and PFOS). Several of these contaminants exceed EPA health standards for drinking water.

Iron and manganese dissolve naturally from the rock layers that make up the county's aquifers as water moves slowly underground. PFOA and PFOS are human-made chemicals that enter groundwater from industrial sites, landfills, and contaminated soil. Nitrate and sulfate also exceed standards here, driven by a combination of natural geology and past or present land use that introduces these compounds into the water.

Groundwater in this county is moderately hard, with elevated iron and manganese as the main mineral drivers. These metals dissolve from the basin rock as water flows through it over time. Most wells across Fairfax County show these mineral characteristics.

Fairfax County wells commonly exceed EPA health standards for iron, manganese, nitrate, PFOA, and PFOS. Iron and manganese at high levels can damage your nervous system and organs over time. Nitrate harms infants and can affect thyroid function. PFOA and PFOS are human-made chemicals linked to liver damage, kidney problems, and immune system weakening.

The moderate hardness in county wells causes orange or brown staining on fixtures and laundry. You may notice a metallic or bitter taste in your water. Scale builds up inside pipes and water heaters, shortening their lifespan. These mineral deposits make soap work less effectively for cleaning.

Testing your well is essential since every well behaves differently--yours could have much higher or lower levels than the county average. A comprehensive metals and minerals panel costs between $200 and $400 and will show exactly what treatment your water needs. Water softeners and iron filters can reduce many of these concerns.