The rum Jungle tailings dam - chemical profile of the subsoil

Abstract

In a survey of soils below the Rum Jungle uranium mine tailings dam parameters measured were pH moisture content particle distribution total Cu water-extractable Cu, Ca and SO4 and acid-extractable Ra. The cation profile had a marked discontinuity at the soil/tailings interface. This was attributed to a complex hydrogeology and to the presence of a reduction zone in the soil immediately below the tailings. The tailings acted as an aquaclude to a water table which fluctuated with the monsoonal season. The reduction zone acted as a cation trap preventing cation transport. The radium concentration dropped to levels acceptable to public health within a few centimetres of the soil/tailings interface.