TEMPORAL ANALYSES OF ABANDONED MINE DRAINAGE (AMD) EFFECTS ON BEAR RUN, INDIANA COUNTY, PA

Temporal Analyses of Abandoned Mine Drainage (AMD) Effects on Bear Run, Indiana County, PA

Bear Run, a headwater stream of the Susquehanna River, is highly impacted by abandoned mine drainage (AMD) from both surface and subsurface coal mining. Large-scale water quality improvement efforts have been ongoing since 2008 in an attempt to reduce the acidity and dissolved metal concentrations within the stream. Construction of the remediation systems is being completed in phases, with the most recent going online in the late summer of 2010. This project looks to examine the annual and seasonal fluxes of four sections of Bear Run to determine the effectiveness of the recently built remediation ponds. Monthly water sampling of each of the stream reaches and outflows are being conducted to better understand the temporal changes in acidity and dissolved metal concentrations of this system. After the construction of earlier phases (both constructed wetlands and limestone pits) , in-stream total iron concentrations dropped 50%, and early results indicate even further decreases with the establishment of the new remediation wetlands system. Targeted sampling during times of high flow will allow for the analyses of the different remediation systems under stressed conditions, as well as determining the time-lag on the outflow from subsurface mines.