1 DEVELOPMENT OF A BIOLOGICALLY-INTEGRATED FOOD-WASTE COMPOSTING SYSTEM Sean Clark Department of Agriculture and Natural Resources, Berea College, Kentucky April, 2000 Introduction 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. Food Waste at Berea College The Berea College food service facility feeds about 1200 students during the fall and spring semesters and about 200 during the summer session. Both pre-consumer and post-consumer waste is generated during the process. Pre-consumer waste includes all foods prepared but not distributed to the students while post-consumer waste is all that remains on the plates when they are returned for washing. In previous years both of these waste streams ultimately flowed to the landfill as sewage sludge because all organic waste was disposed down the drain. In the fall of 1998 students from the Department of Agriculture and Natural Resources of Berea College began a program to collect all pre-consumer waste from the kitchen and use it at the nearby greenhouse and garden area. Two 40-gallon, plastic buckets were placed in the kitchen – one in the preparation area and one next to the washing sink. Kitchen workers were asked to put all food waste in the buckets while trying to minimize the amount of non-organic waste such as plastic wrappers and gloves. Each day the buckets were collected, emptied at the greenhouse, washed, and returned to the kitchen. Because the greenhouse and garden area is located only about 200 yards from the food-service kitchen the buckets could usually be carted without the use