EarthFax designed cover systems for two uranium-mill tailings impoundments covering a total of 94 acres to provide long-term environmental protection. The covers were designed to minimize radon emanation from the tailings, infiltration of precipitation, and post-reclamation settlement as well as to provide long-term (1000 years) protection against erosion.
We collected samples to assess the radiologic and engineering characteristics of the tailings and cover materials, identified appropriate borrow sources, prepared construction specifications and quality assurance work plans, and supervised construction activities associated with placement of the covers. Our investigation of potential borrow sources involved collection of soil samples from hand-dug and backhoe test pits and analysis of these samples in a field laboratory to determine gradation, Atterberg limits, moisture content, in-place density, specific gravity, porosity, void ratio, percent saturation, and Proctor density. We also collected undisturbed soil samples and submitted these samples to an independent laboratory for analyses.
EarthFax identified cover materials to meet multiple project purposes, including minimization of radon fluxes from the covered pile, reduction in moisture movement from the pile to the cover, and minimization of erosion potentials. We also provided quality assurance/quality control services during construction of the cover to ensure that the specifications and the requirements of regulatory agencies were met.