This report summarizes the research efforts of Los Alamos National Laboratory in characterizing raw and spent shale samples from the Occidental Oil Shale, Inc., Logan Wash site in the Piceance Creek Basin of Colorado. Our activities have focused on the interaction of the raw material and the process variables and their influence on the ultimate identify and behavior of the spent shale, the resultant leachates, and the chemistry of other aqueous effluents. Both the raw shale material and the retorting process parameters influence the behavior of spent shale solids. The process parameters define the mineral reactions that occur in the spent shale, and the major and trace element residences and mobilities from the raw shale determine how extensively these elements are incorporated in the spent shale matrix and ultimately the composition of the leachate generated by the spent shale/water interaction. The leachate and the solid waste are dependent variables, and the raw shale and process parameters are independent variables. In this report, we summarize our experimental results, including the mineralogy trace element concentrations in solids, and leaching characteristics of the raw and spent shales. We also discuss implications for water quality, which may be affected by aquifer bridging and leaching of spent shales. A major purpose of our research has been to explore new environmental control strategies and to provide information to supplement other research efforts. 6 tables.