The other side of our food system: Rethinking human waste as a resource

How are human bodily wastes transformed into resources? And how do cultural taboos, sanitation infrastructure, and legal regulation shape and contour the possibilities of that transformation? These are questions that I am investigating in my newest project that examines the use of biosolids (i.e. treated sanitation sludge) in agricultural landscapes of the American Midwest.

Since the early origins of agriculture, farmers throughout the world have used human excrement as a fertilizer, often known euphemistically as “night soil.” Today, however, the use of night soil or biosolids is quite limited in most industrial and post-industrial societies, including the United States. The U.S. Environmental Protection Agency (EPA) estimates that more than 8 million dry tons of biosolids are produced in the country annually, but only one percent is used in American agriculture and USDA-approved organic agricultural operations are prohibited from using it (EPA 2014).

My project centers on new developments in the use of biosolids for energy production and agricultural fertilization. Through participant observation and interviews with farmers and wastewater treatment managers in Ohio and the broader Midwestern region, I am seeking to illuminate how human waste is reincorporated into productive systems. In the process, I am documenting how contemporary sanitation systems are attempting to “close the loop” of nutrient cycling while negotiating a series of challenges, from managing heavy metals in the waste stream to assuaging public fears about the safety of such fertilization techniques.

While some people might not want to think about it, the bodily substances we all produce are important features of our agroecosystems, and how we manage them has significant environmental impacts. Today, projects around the world are looking to rethink humanity’s relationship to its waste, which has implications not only for agricultural fertilization (Preneta et al. 2013) and energy production (Chen et al. 2014) but also water conservation (UNICEF 2014) and urban public life (Chalfin 2014).

Today as many Americans seek out local, organically-produced food, few realize that the residues they flush down the toilet are potential resources for local agricultural production. Unfortunately, they are bound up with other wastes in the sanitation system that prevent their use in organic agriculture. This contradiction, among many others, should force us to consider the other side of our food system and its implications for agricultural sustainability.


Chalfin, Brenda. 2014. Public Things, Excremental Politics, and the Infrastructure of Bare Life in Ghana’s City of Tema American Ethnologist 41(1): 92-109.

Chen, Yu, Gaihe Yang, Sandra Sweeney, and Yongzhong Feng. 2010. Household Biogas Use in Rural China: A Study of Opportunities and Constraints. Renewable and Sustainable Energy Reviews 14(1): 545-549.

Environmental Protection Agency. 2014. Water: Sewage Sludge (Biosolids). Accessed 5 Nov 2014.

Preneta Nick, Sasha Kramer, Baudeler Magloire, and Jean-Marie Noel. 2013. Thermophilic Co-composting of Human Wastes in Haiti. Journal of Water, Sanitation and Hygiene for Development 3(4): 649-654.

UNICEF. 2014. Water, Sanitation, Hygiene: Statistics. Accessed on 5 Nov 2014.


Photo of Dr. Nicholas C. Kawa

Nicholas C. Kawa
The Ohio State University

Dr. Nicholas C. Kawa is an assistant professor in Ohio State's Department of Anthropology. He is also a faculty affiliate for Ohio State's Initiative for Food and AgriCultural Transformation (InFACT). His research interests center on human-environmental interaction, with specific focus on human relationships to plants and soils.

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