Tests were conducted on the Tampa Electric Company`s (TECo) Big Bend Station, Unit 4 flue gas desulfurization (FGD) system to evaluate an option for achieving high sulfur dioxide (SO{sub 2}) removal efficiencies. The option tested was the addition of dibasic acid (DBA) additive. In addition, the effectiveness of other potential options was simulated with the Electric Power Research Institute`s (EPRI) FGD PRocess Integration and Simulation Model (FGDPRISM) after it was calibrated to the system. An economic analysis was conducted to determine the cost effectiveness of each option considered.