IMPACTS OF COAL MINING ON THE SOIL PHOSPHORUS RESERVOIRS: RESULTS FROM THE ABANDONED FRIAR TUCK MINE SITE, SULLIVAN COUNTY, INDIANA

The abandoned Friar Tuck mine site in Sullivan County, Indiana, ceased operation in 1952; however, the site continues to be impaired by acid drainage and contributes to poor water quality in the adjacent Mud Creek. Many areas within the complex have been successfully remediated; however, many areas cannot sustain vegetation after remediation efforts and continue to have surface soil pH<4. Soils in the study area are also poorly developed and shallow. Approximately 250 samples were collected from an area in need of additional remediation efforts, and ~100 samples were collected from an area designated as reclaimed to evaluate metal and phosphorus (P) levels in surface soils. In addition, a subset of samples have been evaluated using detailed P geochemistry to quantify adsorbed, oxide-associated, mineral, and organic P.

The surface soils in the area in need of additional reclamation are dominated by the presence of Fe-oxides, and concentrations of Al, Cu, Fe, Pb, and Zn for some samples are at or above probably effects and threshold effects levels (PEC and TEC). P concentrations are generally low (<25 umol/g) and are dominated by oxide associated P, which is likely related to the extensive presence of Fe-oxides in soils resulting from acid mine drainage. In addition, these P concentrations are considerably lower than those found in other organic-rich deposits, which are usually dominated by mineral and organic P, suggesting the dominance of oxide-associated P is a direct result of the mining process and formation of acid mine drainage. These results suggest that coal mining strips P from soils and impacts P reservoirs in soils. Results from the reclaimed area are underway.