The report gives results of an assessment of a full-scale flue gas desulfurization (FGD) waste disposal operation at the Baukol-Noonan Mine near Center, ND. FGD wastes from the alkaline fly ash scrubbing system are disposed of in the mine area in V-notches (Vees) and in the pit bottoms. A program of evaluating this disposal operation consisted of placement of monitoring wells, physical and chemical sampling and analysis of groundwater and wastes, and environmental and engineering cost assessment. The primary environmental effect potential of FGD waste disposal in mining may be in the generation of leachates showing increased concentrations of sulfate, sodium, magnesium, and (to a lesser extent) calcium. However, such FGD waste disposal when properly practiced reduces potential effects of fly-ash-related leachate generation. Placement of the FGD wastes in Vees appears preferable to pit bottom disposal. The capital cost for mine disposal of FGD wastes (including thickening and filtration prior to disposal) from a 438-MW (net) lignite-fired boiler is estimated at about $10.85 million: the annual operating cost is estimated at about $10.70 per ton.