Evaluation of geotechnical and geohydrologic criteria for potential disposal areas

Long-term stabilization of uranium mill tailings presents unique problems for geotechnical and geohydrologic siting considerations at proposed disposal sites. These include geomorphic conditions of proposed disposal sites such as erosion, river meander, and slope stability; and ground-water considerations of depth to ground water, aquifer recharge, flow, definition of background quality and other aquifer characteristics. Numerous site selection criteria are considered that are different than those used in siting industrial facilities. A formal site selection process has been developed in order to determine suitable sites for long-term stabilization of uranium mill tailings for the DOE-sponsored UMTRA Program. Key factors in this process are regional and site-specific geotechnical and geohydrologic considerations. A multi-phase approach was designed to rank selected sites according to geotechnical/-geohydrologic, engineering, and environmental considerations. This approach is presented in another paper. This paper concentrates on the detailed field investigations used to finalize the geotechnical and geohydrologic characterization of the two highest ranked sites