In its present condition, the dam of the tailings pond is less stable than is recommended by international practice. A surveillance system has been established to observe both vertical and horizontal soil movement and the buildup of stresses in the soil. The stability of the dam depends primarily on erosion by shore processes and the consequent reduction of the counterbalance, as well as the reduction in strength of the Cambrian clay underlying the dam caused by creep and by water percolating to the bottom of the pond. The most critical need is to enlarge the counterbalance and to stop...