[en] The search for domestic energy supplies will lead to increased exploitation of domestic fossil fuels. Vast domestic resources of oil shale may provide a long-term alternative to petroleum-derived fuel products. Practical processing experience with shale oil is limited in comparison to other fossil fuel production since serious industry consideration of shale oil production has not been concerted. Methods proposed for winning shale oil from its deposits range from conventional mining and aboveground retorting technologies to in situ combustion methodology. Although the technical and economic aspects of this wide range of options have been generally studied, the environmental impacts must be assessed, as questions of siting, control technology, licensing, and regulation can strongly affect the best production strategy. Preliminary results are reported from studies on the chemical characterization of effluent residuals from oil shale process wastes, their transport through soils, and toxic effects on plants