A Geochemical Study on the Impacts of Underground Coal Mines

Aneesha Balakrishnan
Ball State University, Department of Geological Sciences, Muncie, Indiana, USA
[email protected]

Acid mine drainage (AMD) is a consequence of pyrite weathering at abandoned coal mine sites and has been classified by the United Nations as the second leading environmental threat, after global warming. The study will be conducted in the Mahanoy Creek Watershed (PA), where AMD is a recognized concern because it severely affects the local waterways for the past several decades. The current project involves collection of water and sediment samples at several sites classified into five groups: Reference stream, Creek, Tributaries, AMD: Seepages and AMD: Tunnels.

The water samples have been analyzed for major ions (sodium, potassium, magnesium, calcium, chloride, and sulfate) using Ion chromatography. The sediment samples collected during 2012 summer will be analyzed for trace metals. Using this data a detailed study will be conducted to answer the following questions :(1) How does the change in meteoritic precipitation affect the relative difference in the aqueous chemistry between the various sample classes? (2) How does the binding of trace metals to the sediments change between the groups. In particular Ochre (yellow boy) samples collected near the AMD seepage and tunnels will be analyzed for difference in trace metal binding.

The results of the study are expected to be of great interest to the passive remediation efforts at the Mahanoy Creek Watershed sites. The trace metal analysis can help to identify more focused remediation methods. Similarly, the study on the effect of precipitation on the aqueous chemistry will permit the modulation (if necessary) of remediation efforts with meteoric precipitation.

AAPG Search and Discovery Article #90157©2012 AAPG Foundation 2012 Grants-in-Aid Projects