Millions of tons of mine tailings and dump wastes occur throughout the United States that contain residual metals of both commercial and environmental interest. Many of these materials contain economic concentrations of copper, silver, and other metals. Other heavy metals such as lead, zinc, and cadmium are found in these materials that may leach into surface and ground water supplies. Many of these tailings and dumps have been on site for many years and have been weathered or oxidized. Therefore, classical biooxidative leaching is not appropriate for these materials. MBX Systems Inc. has shown that bioreductive bacteria can solubilize metals from oxide minerals. MBX Systems Inc. proposes to use these nonacid-generating bacteria to biologically reprocess these waste materials recovering marketable metals to support the operations and removing other metals that are toxic to the environment.