Municipal versus Industrial Waste: Questioning the 3-97 ratio


Chart by the author, based on figures from Royt 2007, Leonard 2010, EPA 1987.

There is an oft-quoted statistic that municipal solid waste accounts for only three percent of the waste in the United States. The remaining 97 percent is industrial. I use that statistic regularly (Liboiron 2013). It appears in Elizabeth Royte’s Garbageland (2007), Annie Leonard’s The Story of Stuff (2010), and in countless academic articles. The 97-3 ratio has become a truism of discard studies. But Director of Research at the New York City Department of Sanitation, Samantha MacBride, noticed that we all seemed to be citing each other.

One of the major contributions of MacBride’s book, Recycling Reconsidered (2014), is that it tracks the 97-3% statistic to its origin and looks at how it was made. She found that “an EPA research study conducted in 1987 constitutes the sum total of knowledge about manufacturing-waste tonnages and disposal practices for the United States as whole (see U.S. EPA 1987 and 1988). This study continues to act as reference to this day” (2011, 91). The study states that about 7.6 billion tones of manufacturing waste is created and disposed of on site, compared to the 250 million tones of municipal solid waste– hence, the 97-3 ratio.

But this number is shady. 

Besides being extremely out-of-date, this data is also self-reported by industry as almost all of this waste is interred onsite “without permit or public knowledge on the industrial property where it was generated (MacBride 2011, 97. Also see Atlas 2002). Moreover, MacBride found additional “government documents that cited other industrial, mining, extractive, and agricultural operations as bringing the total industrial waste tonnage generated in the United States up to around 12 billion tons” (87). These documents also hail from the 1980s and early 1990s and are subject to the same invisibilizing forces of self-reporting, private placement, and time.


Bauxite tailings from mining and processing aluminum near Stade, Germany. WikiCommons.

The 1987 EPA report does not take mining into account, and other studies show that mining is the largest portion of industrial-scale waste. Arn Keeling (2012), a historian and scholar of mining waste, writes that

Although no accurate estimate of global waste volumes exists, estimates range from millions to billions of tons annually (depending on whether coal wastes are included), and the mining industry accounts for the largest proportion of total industrial waste production.

Mining and its wastes are increasing worldwide. In Canada alone, from 2001 to 2008, waste generation from mining activities increased by 55% (Statistics Canada 2012). The 2012 Statistics Canada Report on “Human Activity and the Environment” reported that “Canada’s oil sands industry is the largest solid waste producer in Canada and generated 645 million tonnes of tailings from surface mining operations in 2008 including 547 million tonnes of sand tailings and 98 million tonnes of fluid tailings, which are composed of water, sand, silt, clay and bitumen” (10). Researchers have shown that these tailings are toxic (Kelly et al 2010).

The chart below is extracted from the Statistics Canada report. If we add up the numbers, we end up with 2.5% MSW and 97.5% ISW–we seem to be back to our 97-3 ratio!–except the ISW is missing categories of manufacturing and agricultural waste, and the caveats on municipal solid waste seem to indicate that some of those measures are missing as well.

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Chart from Statistics Canada, 2o12.

In a competing set of numbers taken from the US Congress Office of Technology Assessment (OTA) (Fig 8, below), mining waste is only 1.5 billion metric tons compared to manufacturing waste. If we run the numbers on this report, MSW is 2.9% and all other waste is 97.1%–3-97 wins again! Except there is a radical difference between what mining researcher report and what the OTA reports. Are these numbers more or less reliable than others? Why the difference?

Screen Shot 2016-02-26 at 9.20.33 AM

The difference is water. Mining or not, most industrial waste in on-site surface compounds is water (97%, according to the EPA reports, 100). Much of this watery waste (exactly how much is unknown) is treated and discharged into waterways under Clean Water Act permits issued by EPA or state governments (100). The Clean Water Act in the United States includes allowable levels of contaminants, so some waste is still released through waste water. But whether treatment results in any amount of solid waste (I would assume it does), whether that waste is solid or not (I would assume some is), toxic or not (almost certainly), interred on site or not (I have no good guess), is undocumented, and perhaps even unknown. In Canada, “industrial wastewater treatment and discharge costs were $532.2 million, approximately 37% of total industrial water costs in 2009,” though exactly how much water, water-borne waste, and waste extracted from water that amounts to is not counted (Statistics Canada 2012) .

What we do know is that “[n]ationally, 3 percent of manufacturing waste is not disposed of on site, but rather transported to off-site disposal…and only then is it counted and acknowledged” (101). Yet once again, even while this waste is available for counting, it still presents a problem for accounting. Landfills and incinerators are permitted to receive Subtitle D, or non-hazardous, wastes. Yet, industrial and manufacturing wastes coming from impounds are not regulated in the same way, and are characterized as non-hazardous, even though, “the common designation of ‘nonhazardous’ is misleading because these wastes often contain the same toxic and carcinogenic compounds found in [EPA-designated] ‘hazardous industrial wastes’” (Schaeffer and Bailey 1996, 245, quoted in MacBride 101). So even if we have tonnage for these materials, we do not know what they are tonnages of. Our material analysis still stops at the gates.

Throughout this investigation, you may have noticed slippage between categories of “manufacturing” and “industrial” waste, a few cameos by “commercial” and “construction” waste, and the differentiation between “household” and “municipal” waste. Each has different numbers associated with them, which are further complicated by having to move between both Canada and the United States for data, since no single country seems to have a complete data set. There is an acute and ongoing tension between categories of waste and their counts. Industrial Ecologists who attempt to track material wastes through systems have noted that “[m]aterials consumption is analytically less tractable than energy use. It cannot be satisfactorily reduced to single elementary indicators such as kilowatt-hours or British thermal units.  […] Materials possess unique properties, and those properties provide value, define use, and have environmental consequences. To capture these and other interactions, we must consider an ensemble of measures” (Wernick et al 1996). Researchers are ready to puzzle out this ensemble and fine tune our categories, but first we need measures!

In short, we do not have an idea of the quantity of non-household solid waste produced in North America. When we do have ideas of (sub)quantities, we do not have good classifications, so we do not know what we are quantifying. The 97-3 ratio might be ok to use as an illustrative point of relative scale, but since modern waste is characterized by extreme tonnage, toxicity, and heterogeneity, then we have no reliable data on any of the three things that characterize most waste produced in North America. This means it is hard to take action because we do not have actionable objects or information to act upon. As such, MacBride advocates for “ranting and raving, communicated through democratic channels” for industrial solid waste data (176).

Researchers, citizens, and NGOs are well suited to such ranting. We specialize in asking for data. It seems that it is time to roll out Freedom of Information Act requests, inquiries to the EPA, and to our government officials. Plato is famous for saying that “a good decision is based on knowledge and not on numbers,” but without these numbers we’re sorely lacking in knowledge, and thus in good decisions overseen by public interests and inquiry.


Still from The Story of Stuff (2010).


Works Cited

Keeling, Arn. (2012). “Mineral Waste,” SAGE Encyclopedia of Consumption
and Waste: 553-556.

Kelly, E. N., Schindler, D. W., Hodson, P. V., Short, J. W., Radmanovich, R., & Nielsen, C. C. (2010). Oil sands development contributes elements toxic at low concentrations to the Athabasca River and its tributaries. Proceedings of the National Academy of Sciences, 107(37), 16178-16183.

Leonard, A. (2010). The story of stuff: How our obsession with stuff is trashing the planet, our communities, and our health-and a vision for change. Simon and Schuster.

MacBride, S. (2011). Recycling reconsidered: the present failure and future promise of environmental action in the United States. MIT Press.

Royte, E. (2007). Garbage land: On the secret trail of trash. Back Bay Books.

Statistics Canada. (2012). “Human Activity and the Environment.” Minister of Industry, Government of Canada.

US Congress, Office of Technology Assessment. (1992). Managing Industrial Solid Wastes from Manufacturing, Mining, Oil, and Gas Production, and Utility Coal Combustion, OTA Report No. OTA-BP-O-82. Washington, D.C.: US Government Printing Office.

Wernick, I. K., Herman, R., Govind, S., & Ausubel, J. H. (1996). Materialization and dematerialization: measures and trends. Daedalus, 171-198.