Reclamation Approaches and Techniques for Sodic, Low Ph Spoil in Abandoned Bentonite Mines

Abstract

The chemical and physical parameters of overburden (spoil) and pit bottom materials in abandoned bentonite mined lands in Crook County, Wyoming, were characterized by geologic unit in order to classify materials for defining site specific. treatments during reclamation. Key characterization parameters were found to be saturation percentage, exchangeable sodium percentage, electrical conductivity and pH. These parameters were used to develop proposals for amendment types and rates, physical manipulations of spoil and pit bottom materials, and revegetation species as part of the reclamation plan.Additional key words: exchangeable sodium percentage, abandoned mined lands, acidic material, clay. Scope and Purpose of the ProjectHarza Engineering Company and major subcontractors are working. under contract with the Wyoming Department of Environmental Quality-Abandoned Mine Land program to, in part, perform the following functions relating to abandoned bentonite mines in northeastern Wyoming: 1) Perform an investigation of existing site conditions;2) develop and recommend reclamation procedure and techniques based upon site investigations and existing research applicable to bentonite mine reclamationj 3) prepare plans and specifications for construction/reclamation work; and 4) supervise and manage construction/reclamation activities.The investigation and design phase have been completed and limited construction activities have been accomplished.