The computer program, Ooms/DEGADIS, found on these diskettes and described in the EPA report entitled, 'A Dispersion Model for Elevated Dense Gas Jet Chemical Releases - Volumes 1 & 2' (EPA 450/4-88-006a & b), is a VAX-operational program designed to simulate the dispersion of heavier-than-air gases which are emitted into the atmosphere with significant velocity through elevated ports. The program incorporates the sequential execution of two models. The first one (Ooms) calculates the trajectory and dispersion of the gas plume as it falls to the ground. The second (DEGADIS) calculates the downwind dispersion of the plume after it touches the ground. Users are referred to the Preface in the User's Guide for specific instructions for program implementation...Software Description: The program is written in FORTRAN with specific intent for compilation and execution on a Digital Equipment Corporation VAX computer. Implementation of the model on any other computer system may be attempted at the risk of the user. To facilitate dissemination of the model, it is being provided on two PC-compatible diskettes. The model should be uploaded via modem from a PC terminal to host VAX computer, and several files must then be renamed prior to compilation and execution.