The third volume of a three volume study of the limestone injection wet scrubbing process, is presented. The computerized simulation system is conducted by a combination of three computer programs: (1) the executive section, which provides control and information on the progress of a simulation run; (2) the equipment routines which perform the calculations necessary to model the unit process operations; (3) the auxiliary section which is a collection of routines that provide special calculations for equipment routines, interface other programs and summarize the results of a run. This volume contains a description of this system, operating instructions, a technical note describing the equilibrium program used by the system, a sample data input, and program listings.