Assessment of Pre- and Post-SMCRA Minesoils in the Big South Fork National River and Recreation Area Using Hierarchical Clustering Anaylsis.

In the 1980s, the National Park Service (NPS) began reclaiming former coal refuse dumps within the Big South Fork National River and Recreation Area (BSF) which were created before regulations enacted by the Surface Mining Control and Reclamation Act (SMCRA). Environmental challenges associated with previous mining activities stem from the weathering of geologic materials containing pyrite or other metal sulfides, which upon oxidation begin generating sulfuric acid and solubilizing metal cations (known as acid mine drainage (AMD)). Problem areas still exist in the BSF because many refuse piles were unmapped and remained hidden by forested areas growing in native soils. In 2009, the NPS provided funds to map these hidden minesoils and analyze their physical and chemical properties to determine which sites may be producing AMD and which properties may be inhibiting revegetation. The same analyses were to be made on soils previously reclaimed to judge the effectiveness of the reclamation techniques used.

Field descriptions for physical properties and sampling were completed according to National Cooperative Soil Survey Standards. Chemical properties analyzed included: particle size, acid-base account, pH, exchangeable aluminum, manganese oxides, soil organic carbon, CEC, exchangeable bases, Mehlich I-extractable elements, and total elemental concentrations.

Significant differences in the following properties (averaged) were discovered between the un-reclaimed and reclaimed minesoils: slope, percent rock fragments, dominant lithology, net neutralization potential, pH, extractable aluminum, base saturation, extractable elements and total elemental concentrations. Hierarchical clustering analysis revealed similar findings and highlighted instances where reclaimed minesoils were statistically more similar to un-reclaimed minesoils than to other reclaimed minesoils. This indicated that reclamation efforts may not have been completely successful on these sites. The results of this study can aid the National Park Service with future land management of the minesoils located within the BSF boundaries.