The computer program performs the calculations in the mathematical model of electrostatic precipitation and is documented in other publications. The program predicts collection efficiency in an electrostatic precipitator as a function of particle diameter, electrical operating conditions, collection plate area, and gas properties. It calculates electric field distributions and voltage-current characteristics for wire-plate geometries. It determines particle as a function of particle diameter, electrical conditions, and residence time. It accounts for the nonideal effects of nonuniform gas velocity distribution, gas bypassage of electrified regions, and particle reentrainment by using empirically determined, particle-size-dependent correction factors to reduce the ideal collection efficiency for each particle diameter. The program can predict trends in overall mass collection efficiency caused by changes in specific collection area, applied voltage, current density, inlet mass loading, inlet particle size distribution, and nonideal conditions. The program contains an estimation procedure which can be used in lieu of the rigorous procedure of calculation in order to obtain estimates without having to use large amounts of computer time...Software Description: The program is written in the Fortran IV programming language for implementation on a DEC PDP 15/76 computer, using the DOS-15 V3B operating system. The program has also been implemented on an IBM 370/158, a CDC 7600, and a UNIVAC 1100 with minor changes. It requires 86,334 octal words of core, plus an additional 10,276 octal words of core for system software on the DEC PDP 15/76.