Shirley Basin Uranium Waste Pile Reclamation

The Shirley Basin 400 Pile (North Walker Waste Pile), located in Carbon County, Wyoming, is a large waste pile left behind by uranium mining. Previous reclamation activities of this pile removed and encapsulated waste on-site. Despite this, some degree of unsuitable material remains within the 400 Pile and the current grade is susceptible to erosion.

As the 400 Pile erodes, sediments are carried into Little Medicine Bow River located adjacent to the pile. To mitigate the impacts of this sedimentation, Herrera conducted field investigations and developed a reclamation plan for the 400 Pile. Herrera used the GeoFluveTM fluvial geomorphic landform design method and Calson Natural RegradeTM software to develop a design for regrading and stabilizing the 400 Pile that mimics natural and local features. Regrading of the 400 Pile will include creating and armoring channels throughout the area to promote natural drainage and reduce erosion. A portion of the project area lies in Sage Grouse Core Area (SGCA).

The reclamation design includes creating a “lek” area with vegetation and features designed for sage grouse strutting activities. Upon completion of the regrading, the site will be revegetated and permanently stabilized by seeding locally adapted forbs, grasses, and woody vegetation. Herrera will be providing construction oversight for the project, with construction scheduled to begin in July 2021.