Q: How many additional miles can a ton of food waste that will ultimately be composted travel before there is no longer a net greenhouse gas emissions reduction compared to the existing MSW disposal option?
A: 571 miles is approximately the additional one way transit (collection and long haul) before waste to energy and composting are of equal value from a greenhouse gas emissions perspective.
Municipalities considering implementing organics recovery programs often ask about the greenhouse gas emissions of composting, waste to energy, and landfill and generally how to think about trade-offs in transportation distances between the options.
To help with understanding the relative magnitude of the emissions, here’s a back of the envelope calculation along with some additional variables to keep in mind should your municipality or business be wrestling with the same questions.
Based on national averages, U.S. EPA’s Office of Resource Conservation and Recovery have developed the following greenhouse gas emissions factors for food waste and incorporated them into its Waste Reduction Model:
Net Emissions for Organics under Each Materials Management Option (MTCO2E/Short Ton)
|Compost||Combustion||Landfill with Methane Capture||Landfill Nat’l Average|
|Notes||Aerobic composting only. Does not include anaerobic digestion.||Based on mass burn waste to energy facilities.|
|Note: The negative values means there is carbon storage or an overall greenhouse gas emissions reduction.|
ICLEI’s Solid Waste Emission Activities and Sources Protocol proposes an emissions factor of 0.00014 mtCO2e/wet short ton/mile for use of diesel trucks for long haul transport. 
Putting It All Together
According to the table above, there is a 0.08 mtCO2e/short of food waste benefit for composting compared to waste to energy (-0.2- -0.12= -0.08).
0.08/0.00014 = 571 miles. Therefore, 571 miles is approximately the additional one way transit (collection and long haul) before waste to energy and composting are of equal value from a greenhouse gas emissions perspective.
- From an economic and environmental perspective, recovering food waste locally generally makes sense. It was estimated in 2012 that the cost of long haul transport of commercial food waste from New York City was approximately $4/ton/mile. 
- The fuel efficiency of in-city collection is likely lower than long haul transport. Check with your local sanitation or public works department regarding fuel efficiency of waste collection and incorporate these numbers for a more accurate projection. Similarly, this assumes MSW, recycling, and food waste truck routes are optimized and all trucks are at capacity.
- The greenhouse gas emissions reduction from anaerobic digestion would be even greater than aerobic composting. Toronto uses biogas generated from its anaerobic digester to fuel its trucks. To learn more, check out Harvest Power’s blog on how food waste can fuel its own collection plus produce energy.
- There are other reasons to compost and reduce truck trip besides reducing greenhouse emissions and additional technologies that have not been presented. Please contact Resource Strategies or stay tuned for future blogs to learn more.
 U.S. EPA Waste Reduction Model. Updated June 2013. http://epa.gov/epawaste/conserve/tools/warm/index.html
 ICLEI Local Governments for Sustainability USA. Oct. 2012. U.S. Community Protocol for Accounting and Reporting of Greenhouse Gas Emissions. Appendix E: Solid Waste Emission Activities and Sources, Version 1.0. http://www.icleiusa.org/tools/ghg-protocol/community-protocol/community-protocol-overview
 De la Houssaye, M. and A. White. 2012. Economics of New York City Commercial MSW Collection & Disposal and Source-Separated Food Waste Collection & Composting: Opportunities to Reduce Costs of Food Waste Collection & Recovery. A Global Green USA Coalition for Resource Recovery Discussion Document. http://resourcestrategiesconsulting.com/pubs/NYC_Commercial_EconomicsofCompostingandMSWreport.PDF.