The solid product is a wet sludge of calcium sulfate which can be disposed of easily. So FGD does not eliminate pollution. What it does accomplish is to convert a big problem (emission of large volumes of air contaminated by harmful levels of gaseous SOx) into a small problem (collection and disposal of scrubber sludge). Dealing with the problem of air pollution is not cheap. An FGD system installed in a newly constructed power plant represents about one-third of the total cost of building the entire plant. Energy is also required to operate an FGD system, meaning that for two otherwise comparable power plants, one with.