"A study was conducted to evaluate the physical, microbiological, and chemical conditions of 19 experimental landfills after the completion of a ten-year-long municipal refuse/industrial sludge codisposal project. The simulated landfills were constructed in 1974 and 1975 and operated until September 1983. Data collected during this termination study (June 1984) included observations of overall test cell conditions; chemical analysis of final leachate, refuse, and bottom gravel; physical analysis of refuse, gravel, and clay conditions; microbiological analysis of the refuse; and in-place permeability and specific yield of the refuse. Comparisons between municipal refuse-only cells and municipal refuse/ industrial sludge codisposal cells were made in order to evaluate the effect the industrial sludges had on the decomposition process. The codisposal cells did not appear to be different from the municipal refuse only cells in terms of any of the parameters analyzed. Large numbers of aerobic, anaerobic, and facultative microorganisms, many of which were pathogens, were found in both types of cells. It appeared that the decomposition process was more inhibited by the presence of intact plastic or paper bags and other protective wrappings than by the presence of sludges from battery production, plating operations, water softening, paint pigments, solvent-based paints, petroleum processing or municipal wastewater treatment. Identifiable food wastes and other readily biodegradable materials, including fecal matter in disposable diapers, were found protected from decomposition by such wrappings."