The project objective was to evaluate the use of the Vertical-Tube-Reactor process in the wet oxidation of two wastewaters generated by an underground-coal-gasification experiment. The Laboratory Batch Reactor (LBR), a small vessel of constant volume, was used to simulate the conditions a wastewater would experience in a full-scale Vertical-Tube Reactor (VTR). The scope of work included three phases of laboratory, design, and cost-estimating effort. Phase I involved duplicate LBR runs at six temperature and time profiles and produced total chemical oxygen demand (TCOD), total suspended solids (TSS), and total organic carbon (TOC) removal data for treatability curves. Computer modeling in Phase II yielded reactor configurations of various depths, maximum operating temperatures and reaction times for treating 100,000 gpd of each Hanna IV B underground-coal-gasification (UCG) wastewater. Cost estimates for the facility design and construction provided a basis for comparison of these various configurations. Each configuration was also analyzed for power consumption, equipment limitations, and expected COD reductions. In Phase III a best VTR configuration for each wastewater was selected based on consideration of data in Phase II. Multiple LBR runs were performed at the design operating conditions for each VTR configuration selected and the results were compared with Phase I data and conclusions as to feasibility of treatment of the two wastewaters with the VTR process were drawn. Computer modeling and LBR results show it is technically feasible to treat each Hanna IV B UCG wastewater with the proposed VTR configurations. Data on probable cost for these two VTR applications are provided. 12 figures, 14 tables.