Two water samples were taken from the Rio Blanco Oil Shale Company's Retort 1 more than three years after shutdown of the retort burn. The retort had received considerable flushing. These water samples were screened and profiled chromatographically to ascertain the character of the 20 to 30 ppM total organic carbon remaining in each. The waters were found to contain only organophilic solutes above the one-part-per-billion level. Special detection methods with part-per-billion detection limits for selected hydrophilic indicators proved negative for those indicators. Selected indicators ranged from the most hydrophilic (alkanoic acids, alkylamines, and amides) to the least (phenol). The principal species readily identified by either gas chromatography or reversed-phase liquid chromatography were the light polyalkylpyridines and the polyalkylphenols. The two principal individual compounds detected in each water were 2,4,6-trimethylpyridine and 2,3,5-trimethylphenol. The approximate concentrations of each were 200 ppb for a sample taken from the retort center and 400 ppb for a sample taken from the bottom level. It appears that there is a residual oil reservoir in the retort serving as a source of organophilic solutes. Any organic material now passing out of the retort would be highly organophilic and predisposed to deposit on even slightly hydrophobic surfaces such as oil shale or retorted oil shale. Based on the observations in this report, hydrophilic organic solutes may be presumed to be the key indicators for the interaction between oil shale in situ retort effluent and the surrounding environment. Timely monitoring of such sites and development of highly sensitive detection techniques for this class of materials would permit accurate description of migration pathways. 9 refs., 5 figs., 1 tab.