Major variables reported in this study were retorting temperature, retorting atmosphere (inert, air added, air and CO/sub 2/ added), and groundwater quality (source). All leaching tests were made at atmospheric pressure and most at room temperature. Leaching tests were made with groundwater to observe the ability of spent shale to remove materials from groundwater and the possible ability of those materials to plug the pore structure of the spent shale and to minimize further leaching. The factor having the greatest effect on leachate composition was retort temperature. The presence of CO/sub 2/ during hightemperature retorting suppressed the amounts of baseforming materials generated. All leachates were affected significantly by the groundwater used for leaching. As expected, more material was leached from the retorted Utah shale when the higher-purity groundwater was used. The addition of 2% Wyoming bentonite for the purpose of pH modification to the groundwater used for leaching the retorted shale (780 and 1000/sup 0/C (1,436 and 1,832/sup 0/F) retort atmosphere of air with 15% CO/sub 2/ added) showed that the bentonite had only a small effect on the leaching of monovalent cations and essentially no effect on the movement of the heavy, hazardous cations. The effect of retorting temperature was mixed with the exception of chromium, which increased four- to fivefold in the leachate. The permeability of Utah shale was determined by retorting two cores from Rock 2 at 780/sup 0/C (1,436/sup 0/F) for 48 hours in the presence of air alone. The differences in the final permeability of these cores can be attributed to differences in groundwaters.