The report describes results of a conceptual design and cost estimate for a wet limestone scrubbing system for removal of sulfur dioxide from the flue gas of a new 500-megawatt steam boiler plant, fired with coal containing a 3.5 percent sulfur. The estimate covers all equipment from the broiler breeching to the stack, and includes: limestone storage and processing, slurry scrubbing with stack gas reheater and accessories, and spent limestone slurry pond disposal and water recovery. The capital cost for the scrubbing system installed with a new broiler plant was estimated to be $20.15 million or an incremental cost of $40.30 per kilowatt of installed power. The operating cost was estimated to be $7.20 million per year, or 2.06 mills per kilowatt hour of electricity generated.