No abstract

Food waste has major consequences for social, nutritional, economic, and environmental issues, and yet the amount of food waste disposed in the U.S. has not been accurately quantified. We introduce the transparent and repeatable methods of meta-analysis and systematic reviewing to determine how much food is discarded in the U.S., and to determine if specific factors drive increased disposal. The aggregate proportion of food waste in U.S. municipal solid waste from 1995 to 2013 was found to be 0.147 (95% CI 0.137-0.157) of total disposed waste, which is lower than that estimated by U.S. Environmental Protection Agency for the same period (0.176). The proportion of food waste increased significantly with time, with the western U.S. region having consistently and significantly higher proportions of food waste than other regions. There were no significant differences in food waste between rural and urban samples, or between commercial/institutional and residential samples. The aggregate disposal rate for food waste was 0.615 pounds (0.279 kg) (95% CI 0.565-0.664) of food waste disposed per person per day, which equates to over 35.5 million tons (32.2 million tonnes) of food waste disposed annually in the U.S.

A Life Cycle Assessment (LCA) was conducted to determine the environmental impacts of several waste treatment scenarios for a suburban New York (U.S.) municipality. The study goal was to determine if separate food waste recovery and management was environmentally sounder than waste-to-energy incineration (the baseline case). Three alternatives, enclosed tunnel composting, enclosed windrow composting, and anaerobic digestion with subsequent enclosed windrow composting of residuals, were examined considering the entire residual waste stream (not just separated food wastes). Impact categories assessed were climate change, environmental eutrophication and acidification, resource depletion, and stratospheric ozone depletion. A normalized, aggregated impact assessment was created to compare the treatments across categories. The anaerobic digestion scenario scored best, followed by the tunnel composting and the baseline waste to energy incineration scenarios, and, last, the enclosed windrow composting scenario. Although it was possible to select an alternative that decreased environmental burdens compared to the business-as-usual case, all modeled scenarios resulted in higher overall environmental burdens than savings, underscoring the need to avoid creating waste to conserve resources and reduce environmental burdens, and ultimately lead to more sustainable waste management practices.

Six tonnes of discards and recyclables from three waste districts in a New York suburb were sorted in 2012. The districts were chosen because one had a higher recycling percentage, one had median performance, and one was a low performing district. ASTM standards were followed for the waste composition sorting. The results showed, as expected, that the waste district with the highest recycling rate appeared to have the highest separation efficiencies, leading to greater amounts of recyclable materials being source separated. The waste districts also had different overall waste generation, both in terms of the amounts of wastes generated, and their composition. The better recycling district generated less waste, but had a higher percentage of recyclables in the waste stream. Therefore, in some sense, its waste stream was enriched in recyclables. Thus, although the residents of that district recovered materials at a higher rate, they also left large amounts of recyclables in their discardsas did the residents of the other districts. In fact, the districts only recycled between one quarter and less than half of all available recyclables, so that their discards were comprised of up to one third recyclable materials. This level of performance does not appear to be unique to this Town; therefore, we believe that additional recovery efforts through post-collection sorting for recyclables may be warranted.

Waste management is a complex task involving numerous waste fractions, a range of technological treatment options, and many outputs that are circulated back into society. A systematic, interdisciplinary systems management framework was developed to facilitate the planning, implementation, and maintenance of sustainable waste systems. It aims not to replace existing decision-making approaches, but rather to enable their integration to allow for inclusion of overall sustainability concerns and address the complexity of solid waste management. The framework defines key considerations for system design, steps for performance monitoring, and approaches for facilitating continual system improvements. It was developed by critically examining the literature to determine what aspects of a management framework would be most effective at improving systems management for complex waste systems. The framework was applied to food waste management as a theoretical case study to exemplify how it can serve as a systems management tool for complex waste systems, as well as address obstacles typically faced in the field. Its benefits include the integration of existing waste system assessment models; the inclusion of environmental, economic, and social priorities; efficient performance monitoring; and a structure to continually define, review, and improve systems. This framework may have broader implications for addressing sustainability in other disciplines.