Reliable chemical characterizations of oil shale process water have been difficult to obtain due to the lack of standards and limitations of many available analytical methods. These waters are very complex and contain very high or very low levels of many constituents. Chemical interferences are numerous. This paper describes the collection, preparation, stabilization, and chemical analysis of an in situ produced oil shale process water suitable as a reference sample. The sample was produced during the Laramie Energy Technology Center's 1976 Rock Springs Site 9 true in-situ oil shale combustion experiment and carries the designation ''Omega-9.''The sample was analyzed by 13 separate laboratories using six instrumental techniques and a wide range of wet chemical methods. The results of this survey are presented and discussed. Analytical problems specific to process waters are discussed and recommendations for revised methods and additional research are made. The study demonstrated that many standard analytical methods, such as EPA, USGS or ASTM methods, cannot be used to accurately or precisely determine many water quality parameters in process waters. Poor results were obtained for CN/sup -/, COD, phenols, PO/sub 4//sup 3 -/, solids, HS/sup -/, and others. Instrumental methods, including x-ray fluorescence and neutron activation analysis, produced more accurate and precise results than chemical methods of analysis.