There are many economic, social and environmental reasons to reduce the occurrence of food that is wasted. As communities consider options for managing their food waste streams, an understanding of the volume, composition and variability of these streams is needed to inform the decision-making process and potentially justify the capital investments needed for separation and treatment operations. This more detailed inventory also allows for the estimation of embodied resources in food that is wasted, demonstrated herein for greenhouse gas emissions (GHGs). Pre- and post-consumer food waste was collected from four all-you-care-to-eat Campus Dining Services (CDS) facilities at the University of Missouri, Columbia over 3 months in 2014. During the study period approximately 246.3 metric tons (t) of food reached the retail level at the four facilities. 232.4 t of this food was served and 13.9 t of it (10.1 t of edible and 3.8 t of inedible), was lost as pre-consumer waste. Over the same time period, an estimated 26.4 t of post-consumer food waste was generated at these facilities, 21.2 t of the waste edible and 5.3 t of it inedible. Overall, 5.6% of food reaching the retail level was lost at the pre-consumer stage and 10.7% was lost at the post-consumer stage. Out of the food categories examined, ‘fruits and vegetables’ constituted the largest source of food waste by weight, with grains as the second largest source of food waste by weight. GHGs embodied in edible food waste were calculated. Over the study period an estimated 11.1 t CO₂e (100-yr) were embodied in the pre-consumer food waste and 56.1 t were embodied in post-consumer food waste for a total of 67.2 t. The ‘meat and protein’ category represents the largest embodiment of GHG emissions in both the pre- and post-consumer categories despite ranking fourth in total weight. Beef represents the largest contribution to post-consumer GHG emissions embodied in food waste with an estimated 34.1 t CO₂e. This distinction between the greatest sources of food waste by weight and the greatest sources of GHG emissions is relevant when considering alternative management options for food waste.

Collegiate sporting venues have been leading efforts toward zero-waste events in pursuit of more sustainable operations. This study audited the landfill-destined waste generated at the University of Missouri (MU) football stadium in 2014 and evaluated the life cycle greenhouse gas (GHG) and energy use associated with waste management options, including options that do and do not comply with zero-waste definitions. An estimated 47.3 metric tons (mt) of waste was generated, the majority (29.6 mt waste) came from off-site, pre-game food preparation activities; of which over 96 percent (%) was pre-consumer and un-sold food waste. The remaining 17.7 mt originated from inside the stadium; recyclable materials accounting for 43%, followed by food waste, 24%. Eleven waste management strategies were evaluated using the Waste Reduction Model (WARM). Results indicate that scenarios achieving zero waste compliance are not necessarily the most effective means of reducing GHG emissions or energy use. The two most effective approaches are eliminating edible food waste and recycling. Source reduction of edible food reduced GHGs by 103.1 mt (carbon dioxide equivalents) CO₂e and generated energy savings of 448.5 GJ compared to the baseline. Perfect recycling would result in a reduction of 25.4 mt CO₂e and 243.7 GJ compared to the baseline. The primary challenges to achieving these reductions are the difficulties of predicting demand for food and influencing consumer behavior.

Waste management is a critical sector that needs to co-ordinate its activities with outcomes that impact society. Multi-criteria decision-making methods for waste management have been widely considered using environmental and economic criteria. With the development of new social regulations and concerns, sustainable waste management needs to additionally target socially acceptable practices. Despite the need to aid solid waste management decision-makers in contemplating the three pillars of sustainability, a limited inclusion of social impact has been found in the multi-objective decision-making literature. This study presents a systematic literature review of multi-criteria decision-making methods in solid waste management. The purpose of this study is threefold. (1) Emphasize the application of multi-objective decision-making methods, summarizing the models that have been used and their applications; (2) provide insights into the quantification of social aspects and their inclusion in decision-making methods, providing a list of social indicators collected from the reviewed studies; (3) offer an analysis of stakeholders’ involvement in waste management. From the articles investigated, one can observe the importance of understanding the local context in which the waste management system is located and the necessity of community consultation to recognize the potential challenges and improvements to solid waste management systems. Consequently, the involvement of stakeholders is crucial during the quantification process of social indicators. In alignment with the findings and needs raised by this review, a methodological approach is suggested for integrating optimization, social aspects, and stakeholders under a waste management context.