Frequent Questions

What is the municipal solid waste (MSW) hierarchy?

EPA recommends an integrated, three-tier hierarchical approach to MSW management composed of four components: source reduction, recycling, combustion and landfilling. This comprehensive approach addresses critical junctures in the manufacture, use, and disposal of products and materials to minimize wastefulness and maximize value. The hierarchy favors source reduction to reduce the volume and toxicity of waste and to increase the useful life of manufactured products. Recycling, which includes composting, is the next preferred waste management approach to divert waste from landfills and combustors. The third tier of the hierarchy consists of combustion and landfilling. Combustion is used to reduce the volume of waste being disposed and to recover energy from this process. Landfilling is used for final disposal of nonrecyclable and noncombustible materials. The goal of this approach is to use a combination of all of these methods to safely and effectively handle the MSW stream with the least adverse impact on human health and the environment. EPA believes that each community should choose a mix of alternatives that most effectively meets its needs, looking first to source reduction and second to recycling as preferences to combustion and landfilling. 

Additional guidance on the MSW hierarchy is available in the following memos: 
Memo, Horinko to McWhorter; July 1, 2002 (RCRA Online # 14607
Memo, Cotsworth to Schulz; March 21, 2001 (RCRA Online # 14541)
Memo, Cotsworth to Citizen; May 10, 1999 (RCRA Online # 14353
Memo, Dellinger to Warner; March 4, 1997 (RCRA Online # 14204

These memos are available at the following URL:

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