A New Model for Discarded Municipal Waste Composition in the US

The US EPA has published national-level estimates of MSW management approximately annually since the 1990s. These data are heavily relied upon by researchers, state environmental agencies, local planners, and researchers... [ view full abstract ]

The US EPA has published national-level estimates of MSW management approximately annually since the 1990s. These data are heavily relied upon by researchers, state environmental agencies, local planners, and researchers because of the authoritative nature of the source, the frequency of published estimates, and the availability of the information.  The method used by the US EPA to estimate MSW generation, disposal quantities and waste composition uses a materials flow analysis (MFA) approach.  Data from industry associations, relevant businesses, Department of Commerce, and the US Census Bureau are principally used to create US EPA’s annual MSW management estimates (United States Environmental Protection Agency, 2015b).  In addition, waste characterization studies and other sources are used to supplement the main data sets that the US EPA uses.  An acknowledged limitation with US EPA’s MSW management report is the lack of measured data used to develop waste management estimates.  Additionally, national-level estimates of waste disposal and composition are helpful for understanding big-picture waste management trends, but the lack of granularity limits the utility of such data.

Here we demonstrate a new model of waste composition discarded into MSW landfills, built using three large data sets reflecting facility-level measurements of total waste disposal, categorical waste component (e.g., municipal, construction, and industrial waste) disposal, and individual waste component disposal. Taken together, we portray the most granular, complete, and geospatially-resolved picture of disposal into MSW landfills to date.  We find that a substantial number of the 1100+ landfills reporting data to the US EPA's Greenhouse Gas Reporting Program (which will be used in the US Greenhouse Gas Sources and Sinks estimates) are over-reporting MSW disposal, resulting in an over-estimate in greenhouse gas emissions. Our model will be useful in tracking the efficacy of diversion programs - such as the many food waste disposal reduction efforts taking place across the US - by reflecting changes in waste disposal on a national, regional, state, and local level on an annual basis.