COAL BASIN MINE RECLAMATION CASE STUDY~1

摘要

The State of Colorado, Division of Minerals and Geology, is in the process of accomplishing reclamation of a previously permitted coal mining operation located in a high mountain basin in the central Rockies of western Colorado. Coal Basin is a large erosional feature located on the east facing slope of the Grand Hogback in Pitkin County, Colorado. High average annual precipitation, steep slopes and erosion prone soils combine to create the highly erosive nature of this area. Previously permitted mining operations substantially added to the sediment load in local stream systems. Five underground coal mine portal facilities, developed in the 1950's and 1960's along the steep flanks of Huntsman Ridge, are situated at elevation 3,048 meters (10,000 feet) in this rugged sub-alpine environment. Coal processing facilities, including a wash plant, thermal drier and coal refuse piles are located approximately five miles east of the mine entry areas at the confluence of Coal and Dutch Creeks at elevation 2,530 meters (8,300 feet). Due to the many unique geologic, topographic, environmental and operational challenges of Coal Basin, classic reclamation techniques and concepts were reevaluated and subsequently modified in order to meet the reclamation goals established for the site. Reclamation operations have focused on addressing the many environmental needs of Coal Basin by primarily minimizing active and potential erosion and resultant sedimentation from mining related facilities. The reclamation challenges are being met by implementing large scale geomorphic restoration operations and through innovative steep-slope revegetation practices. To this end, alternative, yet effective, erosion and sediment control techniques have been adopted, and unique revegetation procedures have been undertaken, as the reclamation process continues. This paper provides an overview of some of the techniques and methods used to stabilize this steep, highly erosive site.