This report is on a computer study of the Koh-Chang model for physical fate prediction in dredge material disposal. This computer model can simulate three discharge methods: instantaneous bottom release, jet discharge, and discharge into a wake. Convective descent, dynamic collapse or bottom encounter, and long term diffusion phases of waste behavior are considered. Simulation results are most sensitive to variations in convective entrainment and form drag coefficients in the bottom dump method. In the jet method, the model is most sensitive to convective entrainment and cloud gradient coefficients. Model analysis on a single discharge opening with the results superimposed to represent the entire discharge is often necessary. The model is applied to five field situations for pipeline, hopper dredge, and bottom opening scow. Insufficient field data are available for validation. Modifications to the model have been made by COE-WES and EPA-CERL subsequent to this study.