Composting of municipal solid waste (MSW) is experiencing a dramatic resurgence in the US. Several factors are driving this interest in composting including landfill closures, resistance to siting of new landfills and combustion facilities, public support for recycling, and, in general, the overall costs of waste disposal. Starting with only one demonstration project operating in 1980, the total number of projects in the US has increased to sixteen by July 1991. There are approximately 100 projects in some form of planning or development. One reason some communities are sekniing composting as a waste management option is that sewage sludge and MSW can be co-composted thereby recycling a major portion of the overall municipal waste stream. In 1991, five of the operating facilities have incorporated sludge, with a number of new plants also developing systems with this capability. Generic composting technologies are described followed by a comprehensive discussion of operating facilities. Information is presented on the type of processing system, capital and operating costs, and the status of compost markets. A discussion is also included on the operational problems and challenges faced by composting facility developers and operators. Also presented are facility energy usage and a discussion of the energy implications from the use of compost as a soil and fertilizer replacement. A discussion of cost sensitivity shows how facility costs are impacted by waste handling procedures, regulations, reject disposal, and finance charges. The status of, and potential for, integrating composting into the overall waste management strategy is also discussed, including composting's contribution to municipal recycling goals, and the status of public acceptance of the technology. Finally information and research needs are summarized.
