Holding Basin Containment
In addition to in-situ sequestration of holding basin soils, the ROD selected the installation of a low-permeability vertical wall and horizontal sub-grade cover to mitigate the potential for uranium migration. The soils on the interior of the wall will be treated with the calcium and phosphate-based amendments to promote mineralization of dissolved uranium, while the wall itself will be designed to reduce the hydraulic conductivity by a factor of 10-6. This reduction in conductivity will be consistent throughout the depth of the wall (approximately 95 ft to bedrock) resulting in groundwater flowing around the contamination source rather than through it.