Arsenic in Wyoming Groundwater: Sources & Treatment Fundamentals
Where the Arsenic Comes From
Unlike many contamination issues that stem from human activity, arsenic in Wyoming groundwater is largely naturally occurring. Groundwater flowing through arsenic-bearing shale and sandstone formations, common across parts of western and central Wyoming, can leach arsenic, selenium, uranium, and radionuclides into the aquifer. This means even a well with no nearby industrial or agricultural source can test high for arsenic.
Why It Matters Operationally
EPA's drinking water standard (MCL) for arsenic is 0.010 mg/L (10 ppb). Systems drawing from affected aquifers must treat to meet this limit before the water reaches customers.
Common Treatment Approaches
- Activated alumina adsorption: water passes through a bed of activated alumina media that adsorbs arsenic; the media requi