The evaluation of the environmental impact and treatment requirements of in situ oil shale waters depends on precise and accurate data form the laboratory. Standard laboratory methods perform well on typical waters and wastewaters. But oil shale waters are unusual because of high organic content, high salinity, color, and other properties. Many standard laboratory methods, as well as research methods, were found to have considerable imprecision and inaccuracy when used to analyze process waters from the Omega 9 oil shale experiment.