Reclamation of Waste Rock Material at the Summitville Mine Superfund Site Using Organic Matter And Topsoil Treatments

摘要

The Summitville Mine was a high eelvation (3,500 m) open-pit gold mine located in southwestern Colorado. The mien was abandoned in 1992 leaving approximately 200 ha of disturbed area comprised partially fo two large waste rock piles. Reclamation of waste rock material is challenging due to extreme climatic conditiosn in conjunction with a high acid-production potneital and low organic matter concentration of the material. In addition, stockpiled topsoil at the site is acidic and may be biologically inactive due to long-term storage, and therefore sufficient plant growth medium may be limited. The purpose of this study was to determine the effect of organic amendments (mushroom compost vs biosolids) and topsoil (stockpiled vs non-stockpiled) on aboveground biomass, herbaceous cover, and trace element uptake. An on-site field study was established in 1995 to identify the msot effective combination of treatments for successful reclamation and cover, with mushroom compost being mre effective than biosolids, but did not shwo significant trends relative to trace eleemtn uptake. The use of topsoil did not show a significant response relative to aboveground production, cover, and trace element uptake. This study shows that waste rock materials can be directly revegetated if properly neutralized, fertilized, and amended with organic matter. Additionally, stockpiled topsoil was equivalent in plant growth to non-stockpiled topsoil when neutralized with lime.