ABSTRACT
Acid mine drainage is one of the most persistent industrial pollution problems in the United States. Streams and rivers have been adversely affected by underground mines that have been abandoned for decades. Acid mine drain age originates from metabolic activity of iron-oxidizing bacteria (Thiobacillus ferrooxidans), which catalyzes the oxidation of pyrite. This chapter reports on the occurrence, depth, and position of these bacteria in the wetland pilot system at the Big Five Tunnel at Idaho Springs, Colorado. Control methods include chemical treatments to neutralize toxic constituents and make them insoluble and physical storage to create anoxic environments to inhibit growth of iron-oxidizing bacteria. Further investigations should include occurrence of iron oxidizers in the anoxic zone, presence of sulfate reducers in the aerobic zone, effects of the two algal groups on bacterial populations, and effects of fungus growth in association with manganese-oxidizing bacteria.
