"The full report describes the termination of a five-year, pilot scale project that evaluated methane production and gas enhancement techniques in sanitary landfills. Sixteen simulated landfills were constructed in 1980 and operated until January 1985. Data collected during this termination study consisted of characterization of the trace volatile constituents of the gas generated by the experimental landfills and microbiological analysis of the refuse. The trace volatile organic compounds were found in higher concentrations than previously reported in the literature. Xylenes, ethylbenzene, methylene chloride, toluene, and benzene were found in all of the gas samples analyzed. Xylenes were found in greatest concentrations of the trace compounds analyzed, ranging from 12 mg/m3 to 500 mg/m3. The levels and types of trace organics found in the gas indicate that landfill gas could be potentially corrosive and might contain toxic levels of some compounds. All samples had relatively high aerobic and anaerobic plate counts, Clostridium perfringens. and fungi levels. These same samples indicated relatively low levels of total coliforms, fecal coliforms, fecal streptococci, and gram negative rods. Relative numbers and types of microorganisms appeared to reflect the enhancement technique applied to the cell. For example, the highest numbers of microorganisms were found in a cell that had a sewage sludge enhancement."