Development of a biologically integrated food waste composting system

Sustainable agriculture and food systems depend upon the efficient use and recycling of nutrients in order to minimize dependence on non-renewable resources - such as fossil fuels and mined minerals - and to prevent contamination of ground and surface waters. Yet, as modern food systems continue to industrialize and globalize, environmentally sound nutrient cycling becomes increasingly difficult because of the massive scale and concentration of agricultural production enterprises, food processing facilities, distribution systems, and food service institutions. According to a recent analysis by the US Department of Agriculture, over one quarter of the total edible food in the US is lost to human use each year during the retail, food service, and consumer stages of the food system, resulting in nearly 100 billion pounds of waste (Kantor et al. 1997). Currently, most of this food either ends up directly in landfills as solid waste or finds its way there indirectly as sewage sludge (Gardener 1998). Changes in waste management systems must be instituted in order to turn food “waste” into a resource.

Innovative approaches to handling, processing, and re-routing these wastes can contribute significantly to reducing the waste stream into landfills (Vossen et al. 1999). Moreover, recycling these wastes back to cropland after proper processing can enhance soil fertility and reduce dependence on manufactured fertilizer, resulting in substantial energy savings. Processing food wastes through composting or digestion can also be used to generate energy that would otherwise need to be generated with fossil fuels.

The goal of this project was to develop a biologically-integrated food-waste composting system at Berea College, a small liberal arts institution in eastern Kentucky.