This letter talks about a pilot AMD treatment system that treats seepage from Fran Mine in Clinton County.  This is reportedly the chemically worst discharge from a surface coal mine in Pennsylvania.  The system utilizes sulfate reducing bacteria that not only reduces sulfates but also increases pH and reduces iron and aluminum levels.  The letter describes the set up and how long the water remains in the system and the extent of the sampling.  Data collected include pH, sulfates, alkalinity, total suspended solids, hardness, and acidity.  The letter goes on to give suggestions for the future system operation and gives an overview of the full-scale system project.