Identifying and Further Understanding the Role of Bacteria and Archaea in a Basic Mine Drainage Remediation Site in Tanoma, PA

Acid mine drainage pollutes over 3000 miles of streams and ground water in Pennsylvania alone, and in response many solutions have been developed to counteract the effects of acidic mine drainage. It is estimated by USGS that restoring these watersheds would cost 5 billion-15 billion in total. As economic conditions place limits on expenditures, cost effective means of remediation will be of critical importance. One such method is passive bioremediation, and in the case of metal contamination, self-sustaining oxygenation. Our location of interest is the Tanoma Acid Mine Drainage engineered wetland near Tanoma, Pennsylvania. It is estimated that up to 5,000 gallons per minute is currently being discharged into the site. While most local remediation sites are acidic (pH <4), the Tanoma wetland allows for the study of bioremediation in more neutral pH setting (pH of 5.5-7.5). In this study, we look to further understand biologic, chemical, and hydrologic controls that contribute to the efficiency of the wetland. Our research will focus on the spatial and temporal distribution of biomass through the wetland system as well as changes in water and soil chemistry. Local biofilm (Leptothrix discophora ) are an important part of the remediation process, using iron from the water as an energy source. The bacteria reduce the iron content of the water, precipitating it onto the pond bed as Terraced Iron Formations (TIF). Terraces iron formations (TIF's) are correlated with localized biofilm-archaea densities where archaea thrive in iron rich sediments. By determining bacteria densities in the wetland through gram stain analysis, we can further understand their role in terraced iron formation creation, find localized TIF's that occur, and correlate methane production due to archaea in that location. Mapping TIF locations and identifying bacteria densities will help determine the bioremediation effects on the overall efficiency of iron reduction throughout the Tanoma AMD passive remediation system.