The potential for reduction of sulfur dioxide emissions through coal cleaning is examined for electric-utility power plants in the Ohio, Indiana, and Illinois region. Twenty-four plants burning predominantly high-sulfur coal and having capacities of 500 MWe or greater are identified, and the characteristics of their coal supplies are analyzed. The sulfur reductions attainable via coal cleaning for the various coals are estimated, and the costs are compared with those for equivalent sulfur dioxide reductions using flue-gas desulfurization. Coal cleaning is shown to be a cost-effective option for approximately half of the plants studied, although the total sulfur dioxide reduction potential is much less than for flue-gas desulfurization. Regulatory and institutional considerations relevant to mandatory coal-cleaning requirements are evaluated, as are options for encouraging greater voluntary use of cleaned coal. Actions at the state level to promote greater use of cleaned coal are found to be most likely. 20 references, 14 figures, 17 tables. (ERA citation 08:055423)