Evaluation of the Hydrogeologic System in Disposal of Mixed Wastes.

摘要

Hydrogeologic settings and processes are considered to have a controlling effect on the long-term performance of a multilayered mixed-waste disposal cell. A conceptual modeling of disposal cells indicated that the hydraulic conductivity of the final cover, compared to that of the liner, plays an equal or more important role in determining both the leakage rate from the unit and the breakthrough time. A low water saturation for the disposal facility or a periodic dry condition at the surface can significantly impede downward water infiltration. Analysis also revealed that the emplacement of a disposal cell may cause the water table to shift upward and possibly saturate part of the disposal cell. Seasonal fluctuations of the water table may then carry leachate away from the waste to the aquifer. Therefore, effective design, construction, and monitoring of a mixed-waste disposal cell rely on a comprehensive understanding of infiltration through the land disposal unit and of local hydrogeologic conditions. 9 refs., 4 figs., 1 tab. (ERA citation 14:024150)