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The purpose of this study is to develop a probabilistic technique in evaluating the stability of coal refuse disposal facilities. A review of coal refuse disposal and the variability associated with coal refuse have been presented. The causes of variability both in soil and coal refuse were discussed in detail, and the extent of variability of coal refuse properties were studied. A probabilistic approach named PEM was incorporated to determine the reliability and assess the probability of low factor of safety of coal refuse disposal facilities. A computer model based on the Simplified Bishop Method and PEM principles had been developed to accomplish the probabilistic study, this computer code is named POINT. Several supplemental codes; RANGEN, MONTE, and PEARSON; were also developed for the same purpose. The Pearson's system of distributions was found particularly useful in determining the probable PDF. The term Reliability Index ({dollar}\\beta){dollar} and Probability of Low Factor of Safety (PLFS) were also established to aid the parametric study. In the parametric study, the impact of the input variables on the output factor of safeties were first analyzed. Then, the influence of the extent of variability of individual variables on the safety assessment were studied in detail. This also included the study of relevance of correlation coefficient to the probabilistic approach. Finally, the validity and accuracy of the computer model POINT were proven by directly comparing the results between probabilistic analysis and deterministic analysis. The Monte-Carlo simulation was also performed on the same facility in question to further evaluate the validity of the Point Estimate Method and computer program POINT.