Food waste includes uneaten portions of meals and trimmings from food preparation. Food waste is the largest component of generated and discarded municipal solid waste by weight.
Estimates of the amount of food waste vary widely. EPA estimates that we each discard less than a pound a day or 225 pounds per year. The Garbage Project at the University of Arizona estimated a per person rate of 1.3 pounds every day, or 474.5 pounds per year. The U.S. Department of Agriculture also has higher estimates of food waste than EPA. Food processing facilities work aggressively to ensure their food wastes are recovered and not sent to disposal facilities. EPA data does not include these businesses.
Curbside collection of food waste is found in about 160 American communities. Large-scale projects in Seattle and San Francisco have been effective, but cost, facility siting and vector control are concerns for new projects. Anaerobic digestion facilities that convert food scraps to energy are still uncommon. More than 60 million homes and 500,000 businesses have in-sink food disposers that divert food waste.
Food waste’s share of the solid waste stream increased by 0.1 percent from 1960 to 2009. During the same time, increased package and paper recycling caused food waste’s share of the disposal stream to increase by 39 percent.
Chaz Miller is state programs director for the National Solid Wastes Management Association, Washington. E-mail him at: [email protected]
Food Waste Facts*
- 34.76 million tons or 13.9% by weight.
- 225 pounds per person per year.
- Food waste is 70% water and 30% solids.
- 970,000 tons, a 2.8% composting rate.
- Organic and highly compostable.
- Grocery store food processing trimmings are a prime resource for composting facilities.
- 160 cities and counties collect food waste for composting. Two-thirds of the programs are in the three West Coast states.
The Composting Process:
- Composting is the controlled decomposition of organic matter by microorganisms into a humus-like product by generating heat and energy to destroy weeds, plants and human pathogens.
- Backyard compost piles that include food wastes must be tightly controlled to eliminate pests.
- Tipping fees are usually charged for incoming food waste.
- Incinerated or Landfilled:
- 33.79 million tons or 20.5% of discarded MSW by weight.
- Usually the wettest component of MSW with moisture content of 70% and BTU value one-third of MSW.
- 21.4 million cubic yards or 5.3% of landfilled MSW in 1997.
- Food waste can decompose into methane in a landfill.
- Landfilled food waste weighs from 680 to 1,500 pounds per cubic yard depending on moisture content.
- Food scraps, solid and liquid fats weigh 412 pounds in a 55-gallon drum.
- Packaged foods create less food waste.
- In-sink kitchen disposal units divert food waste to wastewater treatment plants. In many cases, these facilities produce fertilizer or biosolid products.
End Market Specifications:
- Each facility has its own specifications. Non-organic materials such as metals and plastic must be kept out.
Biocycle Magazine, www.jgpress.com
Composting Council of Canada, www.compost.org
Cornell Waste Management Institute, www.cwmi.css.cornell.edu
“Measurement Standards and Reporting Guidelines,” National Recycling Coalition, Washington, www.nrc-recycle.org
“Municipal Solid Waste Generation, Recycling, and Disposal in the United States: 2010 Facts and Figures,” U.S. EPA, Office of Solid Waste, www.epa.gov/epawaste/nonhaz/municipal/msw99.htm
U.S. Composting Council, www.compostingcouncil.org
* Data is from 2010 EPA estimates, except where noted.