Using a direct method to characterize and measure flows of municipal solid waste in the United States
Although there are a myriad of sources of municipal solid waste (MSW) data in the United States, much of these
data are not transparent and are also extremely difficult to find. In addition, the two major methods of quantifying
national MSW flows—the BioCycle State of Garbage in America and the U.S. Environmental Protection Agency (EPA)/Franklin Associates’ MSW “Facts and Figures” report—differ greatly in their reported results. This study, sponsored by EPA Region 9 and concentrating on the state of California, shows how an improved method of MSW measurement can be built upon the foundation provided by the State of Garbage in America (SOG) survey and complemented by an in-depth analysis of state data from various sources within a state. The primary goal of this methodology is to provide reliable, transparent, tonnage-based, and readily available MSW data for use by policy-makers, MSW managers, and the general public. California was used as the starting point because of the high volume of data available for that state, as well as the controversy surrounding its unusual method of collecting and reporting recycling rates. Also, because of California’s size, its recycling tonnage has a large effect on overall U.S. national figures. It is therefore important to accurately quantify MSW management there. Results show that EPA underestimates U.S. MSW generation rates by a significant amount and that the methodology presented produces consistent and replicable results across different states.
There is a great deal of argument over the best ways to deal with municipal solid waste (MSW) in the United States. Many of these arguments are subjective in nature, a prominent example being the “zero waste” goal often advanced by activists.1 Although laudable as an ideal endpoint, a closer look at the data suggests that this is far from being achieved in reality. To promote a pragmatic set of policies around MSW management, a better understanding of the amount and characterization of waste produced in the United States is needed. This is the main focus of this paper—the establishment of a transparent methodology that accurately measures flows of MSW in the country. The methodology is demonstrated using California as a test case. An alternative metric to recycling rates was developed by the authors and will be the subject of a future paper.
EXISTING SOURCES OF U.S. MSW DATA
Currently, there are two major national studies of MSW data in the United States—the U.S. Environmental Protection
Agency (EPA)/Franklin Associates’ “Facts and Figures,” an annual report commissioned by EPA2; and the BioCycle/Earth Engineering Center (EEC) State of Garbage in America (SOG), a biannual study published by BioCycle Journal.3
Franklin Associates uses a form of materials flow analysis (MFA) to perform their analysis. However, it is quite
difficult to assess the effectiveness of their approach because the specific methodology behind their calculations
is not published. A generalized and unpublished description of the original methodology was obtained for this research study.4 Although the steps taken to calculate MSW flows are not clearly delineated in this document, the underlying methodology is apparent—estimates are based on production data for materials and products that end up in the waste stream, and adjustments are made for imports/exports and for the expected lifetime of materials. The report’s bibliography includes many references to the U.S. Department of Commerce, as well as trade organizations like the U.S. Steel Recycling Institute, Battery Council International, etc.
Because collected recyclables are used as feedstock for remanufacturing into new materials, it turns out that the
Franklin methodology (which appears to rely on information received from trade/commodity associations) does a good job of tracking the national trends of traditional curbside recyclables (i.e., metal, glass, paper, and plastic [MGPP]). However, it falls short when it comes to organics collection and, more significantly, in its estimate of tonnage of MSW landfilled. For whatever reason, industrial production data do not seem to provide adequate information for estimating disposal tons.
The SOG survey uses an entirely different strategy. Because most states have regulations requiring landfills and waste-to-energy (WTE) facilities to report tons received, it is possible to obtain reasonable disposal tonnage reports from the relevant regulatory authorities in each of the 50 states. Recycling tons are typically not regulated, but the same agencies tend to keep track of these figures as well, although the numbers are generally not as reliable as the reported landfilled and WTE tonnages.