The objective of this research is to produce sufficient information on the physical and chemical nature of Coolside waste to design and construct physically stable and environmentally safe landfills. This quarterly report consists of three monthly progress reports. The first is on an ongoing field test where additional data obtained during this reporting period support earlier results indicating that mineralogical transformations continue in the field lysimeters as a function of available moisture, aging and static loading of the Coolside materials. The second report presents results from an ongoing laboratory testing which support earlier data that mineralogical transformations cause swell in the FBC ash samples. The objectives of this part of study focuses on long-term changes in permeability of clay liners caused by water leaching through FGD- materials into compacted clay liners. The third report summarizes results from an ongoing investigation of the capacity of dry FGD wastes to absorb acidic gases. This work is part of a continuing effort to identify and evaluate potential commercial applications for FGD waste materials. Results from an investigation of CO{sub 2} absorption in which waste samples were evaluated in both hydrated- solid and aqueous-slurry forms were previously reported. In that study, emphasis was placed on the removal of CO{sub 2} from multi- component gas streams, particularly, natural-gas streams. The current probe is an expansion of the CO{sub 2} absorption study and includes results from testing of H{sub 2}S, SO{sub 2}, NO, CH{sub 4}, and NO{sub 2} absorption. The relative affinity of the dry FGD wastes for the gases examined thus far was found to be SO{sub 2} > CO{sub 2} > H{sub 2}S. CH{sub 4} and NO are not absorbed and NO{sub 2} apparently decomposes on contact with surface water to NO and HNO{sub 3}.