Decades of unrestricted subsurface excavation dangerously undermined most of Picher's town buildings and left giant piles of toxic metal-contaminated mine tailings (known as chat) heaped throughout the area. The discovery of cave-in risks, groundwater contamination and health effects associated with the chat piles and subsurface shafts resulted in the site being included in 1983 in the Tar Creek Superfund site by the US Environmental Protection Agency.
Decades of unrestricted subsurface excavation dangerously undermined most of Picher's town buildings and left giant piles of toxic metal-contaminated mine tailings (known as chat) heaped throughout the area The discovery of cave-in risks groundwater contamination and health effects associated with the chat piles and subsurface shafts resulted in the site being included in 1983 in the Tar Creek Superfund site by the US Environmental Protection Agency