Reclamation at the richmond Hill Mine, lawrence county, south dakota

摘要

The Richmond Hill Mine has recently completed a reclamation plan to mitigate Acid Ricl Drainage (ARD) which was identified at the toe of the former waste rock pile in 1992. Reclamation activities began in 1994 with the removal of ARD material from the waste rock pile and placement of this matrial in the former pit. This material was then isolated from the near surface environment by a low permeability capping system designed to minimize water and oxygen flow into the material. The cappling system consists of from bottom to top, six inches of limestione, 18 inches of low permeability clay liner, 4 and one-helf feet of thermal barrier/drain layer, and six inches of topsol. This capping system was completed in 1995.