Food Waste Research
On this page:
- Why research food waste?
- From Farm to Kitchen: The Environmental Impacts of U.S. Food Waste
- From Field to Bin: The Environmental Impacts of U.S. Food Waste Management Pathways
- Quantifying Methane Emissions from Landfilled Food Waste
- Emerging Issues in Food Waste Management
- Research Highlights
Why research food waste?
Wasted food is a major global environmental, social, and economic challenge. According to scientific research, approximately one-third of the food produced in the U.S. is never eaten. When food is produced but unnecessarily wasted, all the resources used to grow the food – water, energy, fertilizers – and the resources used to transport it from farms to our tables, are wasted as well. Most of the resource inputs and environmental impacts of food waste occur during production, processing, and delivery to our kitchens. When food is deposited in a landfill and decomposes, the byproducts of that decomposition process are methane and carbon dioxide. Methane is a potent greenhouse gas that traps heat and contributes to climate change. EPA estimated that in the United States in 2018, more food was sent to landfills than any other single material in our everyday trash (EPA Advancing Sustainable Materials Management: Facts and Figures).
In 2015, EPA and the U.S. Department of Agriculture (USDA) established a national goal to halve food loss and waste by 2030. Through the sustainable management of food, we can help businesses and consumers save money, provide a bridge in our communities for those who do not have enough to eat, prevent pollution, and conserve resources. Research and development of new science-based solutions are essential to meeting these goals. Below are examples of EPA research to reduce food waste and improve its management.
From Farm to Kitchen: The Environmental Impacts of U.S. Food Waste (Part 1)
EPA prepared the report, From Farm to Kitchen: The Environmental Impacts of U.S. Food Waste, to inform domestic policymakers, researchers, and the public about the environmental footprint of food loss and waste in the U.S. and the environmental benefits that can be achieved by reducing U.S. food loss and waste. It focuses primarily on five inputs to the U.S. cradle-to-consumer food supply chain -- agricultural land use, water use, application of pesticides and fertilizers, and energy use -- plus one environmental impact -- green house gas emissions.
Read the report: From Farm to Kitchen: The Environmental Impacts of U.S. Food Waste.
From Field to Bin: The Environmental Impacts of U.S. Food Waste Management Pathways (Part 2)
EPA prepared the report, From Field to Bin: The Environmental Impacts of U.S. Food Waste Pathways, to investigate the environmental impacts and contributions to a circular economy of eleven common pathways to manage wasted food – from source reduction to composting to landfill. The report presents a new ranking of the wasted food pathways, from most to least environmentally preferable. Wasted food is generated all along the food supply chain, and thus the audience for this report includes a broad range of stakeholders from farms to food businesses to households to waste managers, as well as policymakers seeking advice on how to reduce the environmental impacts of wasted food. This report completes the analysis that began in the Part 1 report, From Farm to Kitchen: The Environmental Impacts of U.S. Food Waste. Together, these two reports provide a better understanding of the net environmental footprint of U.S. food waste.
Read the report: From Field to Bin: The Environmental Impacts of U.S. Food Waste Management Pathways
Quantifying Methane Emissions from Landfilled Food Waste
Methane is a powerful greenhouse gas that affects the earth’s temperature and climate system. Municipal solid waste landfills are the third largest source of methane emissions in the United States. Methane emitted from landfills results from the decaying of organic waste over time under anaerobic (i.e., without oxygen) conditions. To understand the impact of landfilled food waste, a portion of organic waste, has on these emissions, EPA developed the report, Quantifying Methane Emissions from Landfilled Food Waste. The analysis estimates the amount of methane emissions released into the atmosphere from decaying food waste in landfills from 1990 to 2020. This is the first published modeled estimates of national annual methane emissions from landfilled food waste. Results of the analysis can inform actions to reduce the amount of wasted food being disposed of in landfills and consequently, the methane emitted.
Read the report: Quantifying Methane Emissions from Landfilled Food Waste
Emerging Issues in Food Waste Management
EPA encourages the recycling of food waste for several reasons. Recycling food waste can reduce methane emissions from landfills, and it can recover valuable nutrients and energy from food waste. However, there are concerns about the levels of plastic and persistent chemical contaminants, including per- and polyfluoroalkyl substances (PFAS), in food waste streams. Food waste streams consist of food and other items (such as compostable food packaging) that get collected – intentionally and unintentionally – for composting or anaerobic digestion.
EPA recently developed two reports summarizing published science about contamination in food waste streams, the effects of this contamination on composting and anaerobic digestion (two common ways to recycle food waste), and potential risks to human health and the environment of applying compost or digestate (the product from anaerobic digestion) made from food waste streams to land as soil amendments.
Another EPA report summarized the available data on food waste technologies, such as grinders and biodigesters, used by businesses and institutions to pre-process food waste on-site. The report evaluates whether these technologies encourage food waste recycling or reduce the environmental impact of food waste. These reports are available at the links below.
Emerging Issues in Food Waste Management: Persistent Chemical Contaminants
The purpose of this issue paper is to inform policymakers, producers of food waste compost, and potential buyers of compost and digestate about the contribution of food waste streams to persistent chemical contamination in compost and digestate, relative to other common feedstocks, and the potential health and environmental risks posed by land applying compost and digestate made from food waste.
Emerging Issues in Food Waste Management: Persistent Chemical Contaminants (pdf)
Emerging Issues in Food Waste Management: Plastic Contamination
The purpose of this issue paper is to inform federal, state, and local policymakers of the latest science related to plastic contamination in food waste streams and its impacts on food waste recycling, the environment, and human health, and to prioritize research needs in this area.
Emerging Issues in Food Waste Management: Plastic Contamination (pdf)
Overview: Emerging Issue in Food Waste Persistent Chemical and Plastic Contamination (pdf)
Emerging Issues in Food Waste Management: Commercial Pre-Processing Technologies
The purpose of this issue paper is to assess the environmental value of food waste pre-processing technologies (e.g., biodigesters, grinders, and pulpers) used on-site by businesses and institutions that generate food waste.
Emerging Issues in Food Waste Management: Commercial Pre-Processing Technologies (pdf)
Overview: Commercial Pre-Processing Technologies (pdf)
Research Highlights
Food Waste Prevention and Reduction
U.S. EPA Excess Food Opportunities Map
This map displays the locations of about 950,000 potential industrial, commercial and institutional excess food generators, about 6,500 potential excess food recipient locations, and about 275 communities with residential source separated organics programs. The map enables users to learn about potential sources of excess food in their region and potential non-landfill recipients, such as food banks as well as composting and anaerobic digestion facilities. As part of EPA’s Office of Research and Development’s (ORD) Regional Sustainable Environmental Science (RESES) program, EPA researchers from Region 9, ORD, and the Office of Land and Emergency Management (OLEM) collaborated to develop the map. OLEM currently manages and updates the map. Version 3.0 was released in August 2023. Read a story about the map here.
Food Waste Reduction in Military Kitchens, A Tracking Technology Demonstration at Fort Jackson
EPA researchers, in partnership with the U.S. Army as part of the Net Zero initiative, conducted a demonstration with the Leanpath food waste characterization technology to assess how overproduction and food preparation practices contribute to food waste in U.S. Army-operated dining facilities. As a result of the project, the Army was better able to understands the drivers of food waste in Army kitchens (primarily over-production), and over five tons of unused food identified in the project was donated to local food banks. This project was part of EPA ORD’s Net Zero Partnerships.
Organic Waste Diversion Feasibility Study in Columbia, South Carolina
EPA scientists identified and analyzed major food waste generators and opportunities to divert food waste from landfills. The study helped inform local and state efforts.
Food Waste Processing
Evaluating Processed Food Waste from Kitchen Digester Use and the Downstream Impacts/Benefits
Growing demand for handling food waste in environmentally friendly ways have led to aggressive marketing for and purchasing of a variety of on-site food waste processing systems. EPA researchers are studying pre-processing technologies in use in commercial kitchens in New York City. The results of this research will assess and evaluate food waste pre-processing systems in real-world settings with respect to factors such as performance, capital costs, existing infrastructure, quantity and quality of waste and water streams, and its overall potential to enable organic waste reduction and diversion.
Methods for Characterization of Plastics Contamination in Food Waste from Depackaging Facilities
Plastic contamination of food waste may complicate composting and anaerobic digestion operations. Since the plastics in food waste are most often associated with packaging and containers, large food waste processors are increasingly implementing de-packaging technologies as a primary means of removing the plastic contamination.
EPA researchers tested the performance of food de-packaging equipment available on the market through the collection and analysis of food waste samples from organics processing facilities around the U.S. Researchers identified plastic polymers including polyethylene, polypropylene, polycarbonate, and polystyrene, showing that some polymers can remain after the de-packaging process. As industry and communities make further improvements in removing plastics from food waste streams, there are still key challenges when considering the goal of eliminating residual plastics in food waste to limit the formation of microplastics and nanoplastics and their spread in the environment.
Food Waste Management
Effect of Nutrient Removal and Resource Recovery on Life Cycle Cost and Environmental Impacts of a Small-Scale Water Resource Recovery Facility
Scientists conducted a scenario analysis of upgrading a small community water resource recovery facility to include anaerobic digestion with co-digestion of high strength organic waste. Life cycle assessment and life cycle cost assessment were used to evaluate the net impact of the potential conversion. The upgraded water resource recovery facility reduced eutrophication impacts by 40 percent compared to the legacy system.
Feasibility Study of Food Waste Co-Digestion at U.S. Army Installations
EPA researchers worked with the U.S. Army Engineer Research and Development Center to assess the feasibility of rebuilding the sewage treatment system at Fort Huachuca, Arizona to include anaerobic digestion to accept food waste and other organics. The research team concluded that co-digestion of food and biosolids would be a win-win scenario for Fort Huachuca because it would help eliminate the largest part of the waste stream (food), reduce biosolids disposal costs, and generate power for operating the installation’s wastewater treatment plant.
Life Cycle Assessment and Cost Analysis of Water and Wastewater Treatment Options for Sustainability: Upgrade of Bath, New York Wastewater Treatment Plant
EPA scientists investigated the potential trade-offs within the context of a Southwestern New York community of upgrading a one million gallon per day conventional activated sludge system to incorporate advanced biological treatment and anaerobic digestion, including co-digesting an increased quantity of the community’s high strength organic waste. The life cycle assessment explored methods to upgrade the wastewater treatment plant, while simultaneously transforming it to recover useful energy for heat and electricity, nutrients for compost, and water for irrigation. The research provides guidance for small communities considering upgrades and demonstrates the positive potential of resource recovery strategies to increase effluent quality while reducing other environmental impacts.
Food Waste to Energy: How Six Water Resource Recovery Facilities are Boosting Biogas Production and the Bottom Line
EPA researchers evaluated the co-digestion practices, performance, and the experiences of six water resource recovery facilities accepting food waste. The report describes the types of food waste co-digested and the strategies--specifically, the tools, timing, and partnerships--employed to manage the material. Additionally, the report describes how the facilities manage wastewater solids, providing information about power production, biosolids use, and program costs.
Impact of Food Waste Diversion on Gas and Leachate from Simulated Landfills
EPA researchers evaluated the quality and quantity of liquid and gas emissions from lab-scale landfills (lysimeters) with varying amounts of food waste. In the simulations, those with the least amount of food waste began generating methane the fastest, contradictory to how current models predict landfill methane generation. This finding showed that food waste contributes volatile fatty acids to municipal solid waste, which in turn lowers pH and delays microbial methanogen dominance.