Codisposal of solid wastes and low-quality aqueous effluents from oil shale operations is among the disposal methods being considered for these wastes. A preliminary experimental evaluation of this practice focused on the validation of analytical techniques for studying the chemistry that occurs when these wastes are mixed. Three shale types were contacted with a single retort water to evaluate the effects of shale type and surface area on the behavior of organics when in contact with solid shales and the mobilization of inorganics within solid shales. Distilled water leachates from these shales were used as the baseline case. The inorganic compositions of distilled water and retort water leachates were compared. The pH and conductivities of these leachates suggest that the ultimate compositions of leachates from codisposal are dependent on both the shale type and the leaching medium. The concentrations of the trace elements suggest that they are mobilized by the retort water leaching medium. This mobilization probably is due to complexation by organic ligands or by increased solubility caused by the ionic strength of the leaching medium. The organic compositions of these leachates are dependent on the shale type. Because of the nature of the analytical methods, only about 5 wt% of the solvent extractable material was analyzed. However, previous work suggests that the material being analyzed contains the majority of the mutagenic compounds.