Well Water in Inyo County: What to Test and Why

Groundwater in Inyo County contains arsenic, chloride, fluoride, iron, manganese, nitrate, radon, sulfate, and uranium at levels that exceed EPA health standards. Several of these contaminants--including arsenic, uranium, and radon--are serious health concerns that well owners should test for and monitor.

These contaminants come from the natural rock beneath the county. The carbonate and other rock layers in this Basin and Range area naturally contain minerals and radioactive elements like uranium and radon. Chloride and sulfate also come from the rock itself, released as groundwater slowly moves through it over years. Agricultural activity and urban land use add nitrate to some wells in the area.

Groundwater in this county is very hard, driven by high levels of sulfate and sodium along with elevated calcium and magnesium from the limestone and carbonate rock below. The rock structure in this region traps mineral-rich water, allowing these elements to build up over time. Hard water and elevated sulfate are widespread across wells throughout the county.

Wells in Inyo County commonly have arsenic, uranium, radon, fluoride, and nitrate above EPA health standards. Arsenic and uranium are toxic metals that build up in your body over time and raise the risk of cancer and kidney damage. Radon is a radioactive gas that increases lung cancer risk when you breathe it in. Fluoride at high levels can damage your bones and teeth. Nitrate harms infants and people with certain blood disorders.

The water in this county is extremely hard with very high sodium and sulfate levels. You will see white scale buildup on faucets, showerheads, and inside pipes and appliances. Hard water reduces how well soap works and can shorten the lifespan of your water heater and dishwasher. The high sodium gives the water a salty taste. Reddish or brownish stains on fixtures come from iron in the water.

Testing is the only way to know what is actually in your well. Every well is different, and your water could have higher or lower levels than what is common here. We recommend a comprehensive water quality panel since multiple contaminants exceed health standards in county wells. A full panel costs between $200 and $400. Treatment options like reverse osmosis, aeration systems, or water softeners can address different problems depending on what testing finds.