Linking upstream mining to downstream water quality: Mountaintop mining in West Virginia

Abstract

Mountaintop mining valley fill (MTM/VF) coal mining is currently the dominant form of land use change in the central Appalachians. MTM/VF activities level mountains, remove forests and forest soils, bury headwater streams and generate substantial amounts of acid and alkaline mine drainage. Numerous case studies have documented elevated concentrations of sulfate and trace metal and metalloids with known toxicity in surface waters downstream from MTM/VF activity, yet no comprehensive effort has been made to link landscape scale mining activity and water quality. Here, I used newly obtained remote sensing data of surface mining activity delineated from 1976 to 2005 to estimate the extent of MTM/VF impact on downstream surface water quality in the Coal and Guyandotte river basins of WV. Hydrologic connectivity between mining and water quality was estimated using an inverse distance weighting technique in GIS (ESRI, Inc.). The findings show significant biogeochemical alterations, including streamwater conductivity and sulfate concentrations, even when small amounts of surface mining (<5%) are observed. Results provide the first comprehensive analysis of the cumulative impact of mining activity in these watersheds on water quality and demonstrate the need for further investigation involving strategic water quality sampling with the ultimate goal of developing an empirical basis on which to form regulations governing MTM/VF throughout the central Appalachians.