The physical composition of the municipal solid waste stream will vary from region to region based on a number of factors including, among other things, the waste generation practices of a municipality’s population and businesses, the extent of recovery programs that divert solid waste components before collection, and the effect of the informal sector in recovering materials of value from collection containers prior to collection. Generally, waste composition assessments are important in determining the extent of recoverable materials within the waste stream so as determine the technical and economic viability of recovery and recycling programs. Assessments can also help to determine the extent of biodegradable material that must be treated prior to disposal.
Given the typical variability of a municipal solid waste stream, the extent of sampling and sorting required in any locale to generate reliable Waste Composition Study data is a function of the required confidence level of the assessment results. For example, the investigation of a major investment in recycling infrastructure may justify a need for a high confidence level in characterization data. Moderate confidence level may be justified to properly assess the recycling and recovery opportunities that may exist in the certain region based on existing market opportunities for recoverable materials.
The following describes a basic process by which a municipal solid waste composition study could be conducted.