Superfund Site Profile
The Perham Arsenic site is located in Perham, Minnesota. It consists of a six- to eight-foot deep pit and associated groundwater plume. From the 1930s to 1947, a facility mixed U.S. Department of Agriculture-supplied arsenic with sawdust and molasses on site; the mix was used as a pesticide to control an outbreak of grasshoppers threatening crops throughout the Midwest.
In 1947, around 200 to 2,500 pounds of arsenic pesticide was buried in a shallow pit. This contaminated soil and groundwater with arsenic. In the 1970s, an adjacent property owner discovered a contaminated well after 11 employees reported being poisoned by arsenic-contaminated groundwater; the property was connected to the public water supply system. Following cleanup including a removal action, treatment system and a site landfill cap, operation and maintenance activities are ongoing.