Water quality changes of underground mines in northern West Virginia

Acid mine drainage (AMD) is a serious problem from both abandoned surface and underground mines, and about 10,000 km of streams have been impacted by AMD in the northeastern U.S. (Pennsylvania, Maryland, Ohio, and West Virginia). Streams in the region have shown improvement over time and this improvement has been partly attributed to reclamation of mined sites and natural attenuation of AMD impacts. This study was initiated to determine the water quality changes from underground mines over time in northern West Virginia. In order to compare chemistry data across years and seasons with varying flow, relationships between discharge rates and acidity values were assessed. Results indicate that water quality from the majority of abandoned, above drainage underground mines did significantly improve over time, some exponentially and some linearly. The amount of improvement varied with coal seams. Graphs plotting flow and precipitation showed the highest flows generally in the spring and low flows in the fall. Acidity concentrations from two underground mines did not change significantly with varying discharge rates, which neither supports previous ideas of a flushing or dilution of acid salts from the mine. One mine, T&T, showed a slight trend of highest acidity values at high flows, while Omega showed highest acidity at low flows. Additional long term data sets with frequent flow and acidity data will be necessary to confirm these results