This is an award to provide support for research by this Presidential Faculty Fellow who will study the anaerobic decomposition of organic compounds that are contained in wastes that are placed in landfills. The investigator plans on determining the effects of organic substances on the decomposition process and will work toward characterization of the dominant microorganisms that are involved in the decomposition process. The recipient of this award was selected by a process described in NSF 91-103, Presidential Faculty Fellows Program, FY 1992 Program Announcement. This investigator's research is likely to lead to a better understanding than now exists of anaerobic decomposition processes that result in the decomposition of organic substances that are placed in landfills. This in turn is likely to lead to improvements in engineering design and operation of such waste management facilities.