Copper Stain: ASARCO's Legacy in El Paso

“The convertors would spew it out,” employee Arturo Hernandez recalled, referring to molten metal. “You’d see the ground, the dirt, catch on fire. . . . If you slip, you’d be like a little pat of butter, melting away.”

Hernandez was describing work at ASARCO El Paso, a smelter and onetime economic powerhouse situated in the city’s heart just a few yards north of the Mexican border. For more than a century the smelter produced vast quantities of copper—along with millions of tons of toxins....