"A significant environmental concern associated with the development of an oil shale processing industry relates to the handling, containment, treatment, use, and disposal of aqueous by -products associated with oil shale processing. Aqueous byproducts may include the leachates from raw and spent shale, process waters recovered with the oil, and subsurface waters associated with production zones Such effluents are generally heavily contaminated with high levels of both organic and inorganic constituents. Possible mechanisms for bioenvironmental contact of aqueous effluents derived from in situ oil shale processing include accidental, episodic exposure resulting from failure of a containment, leakage during transfer or treatment processes, or contamination and subsurface migration of ground waters to a surface outlet. The magnitude of plant responses and phytotoxic effects resulting from such exposure has not been but needs to be quantified for purposes of risk assessment. The development of control technologies for aqueous effluents looks forward to the potential of using suitably treated process waters for land reclamation purposes. Again, quantitative data on plant responses would both provide rationale for water treatment and assess treatment efficacy for waters destined for surface disposal . In response to these needs, a research project to address plant and process water relationships has been developed. The initial objectives of the project are to I) develop quantitative, short-term, cost-effective, diagnostic screening procedures for vegetation, 2) using such procedures, to quantitative the response of selected plants to process waters derived from in situ oil shale processing, and 3) provide information for developing control technology. In the latter objective the information most useful will be in terms of indentifying toxic fractions and testing the effectiveness of specific water treatments to remove such materials. This paper presents results meeting the first-stated objective. Two screening procedures, a seed germination assay and growth and development response assays, have been developed using an in situ oil shale process water."