A significant potential for adverse impact on the Nation's groundwaters now exists due to increased land disposal of solid and liquid residual wastes, particularly hazardous wastes. Concurrently, there has been an increase in the amount of waste being generated, and many wastes continue to be disposed of in a 'least-cost' way which contributes to environmental degradation. Landfilling, ponds, lagoons, and other indiscriminate land-disposal methods have proven in numerous instances to be ineffective for adequate protection of the health of both the public and the environment, particularly where hazardous wastes are involved. This can also be attributed to poor management practices, since technological and management guidelines regulating such disposal practices have, for the most part, been only recently enacted. The overall objective of this investigation is to provide a state-of-the-art assessment of pollution prediction techniques for waste-disposal siting. This assessment includes both current research and regulatory procedures relative to the land disposal/treatment of waste for the entire waste spectrum, exclusive of radioactive wastes. The emphasis, however, is on that research and those regulatory procedures that deal specifically with hazardous waste. Furthermore, the emphasis is on those techniques which lead to pollution prediction through an assessment of attenuation of waste leachates.