Report examines the contamination of earth covers by uranium mill tailings. The researchers studied the Riverton tailings pile for the report, from which they attempted to determine: the distribution and concentration of salt, trace elements and radionuclies through the cover and into the tailings; the concentration of salts and other contaminants in the earthen cover from chemical migration; the relationship between the migration of major elements and trace elements; a possible model of the mechanism that promotes and slows this migration; and the chemical and physical properties of the cover which influence the migration.