Commercial Composting

Composting can reduce landfill waste and greenhouse gas emissions.

Composting is a controlled decomposition process that turns organic materials such as food waste, manure, and yard trimmings into a nutrient-rich earthy material. Compost can be used as a soil additive or as mulch (EPA 1 2022).

• Compost improves the nutrient content in soil, reducing the need for chemical fertilizers (EPA 1 2023).
• Compost holds large amounts of water, which reduces runoff and helps prevent erosion (EPA 1 2023).

24% of waste in landfills is food waste and 7.2% is comprised of yard trimmings (EPA 2 2022).

• 4% of food waste that was generated in 2018 was composted (EPA 2 2022).

During decomposition, organic waste in landfills release greenhouse gases (GHGs), methane and carbon dioxide, which trap heat in the atmosphere (EPA 2 2023). Landfills produce 15% of the U.S.’ methane emissions (EPA 2 2023).

• Composted organic materials produce up to 93% less GHG emissions than landfills due to differences in decomposition processes (Vergara 2019).

Commercial composting can be economically challenging.

Composting can be done in a single household and at large, commercial scales. Composting is influenced by input material, moisture, oxygen, and temperature, and can require technical skill to be done properly (EPA 3 2023, EPA 1 2022).

There are three main ways to perform large scale composting: windrow, aerated static pile, and in-vessel (Table 1; EPA 3 2023).

Table 1. Comparison of different commercial composting methods (EPA 3 2023).

Few studies investigate the profitability of commercial composting.

• One study found that a commercial- scale compost system (20,000 metric tons/year) accepting yard trimmings and wastewater/ sewage would take about 5 years to pay back the initial investment and provide positive returns on investment (Lin 2019).

A voluntary survey of composting operations in the U.S. found that the number of compost programs has more than doubled since 2016 and the average size of each program has increased (Libertelli 2023).

• The most common revenue sources included collection service fees and compost sales. In MO, bulk compost can be sold for about $20—$43 per cubic yard (CO n.d.; STL n.d.; KC 1 n.d.). Compost pickup services in MO can cost from $16—$30 per month (PCC n.d.; KC 2 n.d.).
• About 35% of respondents self-reported that they generate enough income to sustain themselves without grants, crowdsourced funding, or donations; it is not clear how generalizable these data are due to the voluntary nature of the survey.

Federal and state grants support composting projects.

Federal Policies. The U.S. Environmental Protection Agency Climate Pollution Reduction Grant will fund state, municipality, tribal, and territorial programs ($250 million planning, $4.6 billion implementation) to reduce GHGs, including compost programs (EPA 4 2023).

The U.S. Department of Agriculture’s Compost and Food Waste Grant has up to $9.5 million for pilot projects to plan and implement municipal compost projects.

State Policies

Six states (CA, CT, VT, MA, NY, RI) have passed laws that restrict certain generators of food waste from using landfills.

• These restrictions encourage generators of food waste to find other ways to manage their waste, including reducing their output, donating excess food, and composting (NCSL 2022).

Several states, including WA, NC, KY, CA, and ME, have had or currently have applications for grants for compost projects of up to $500k.

The MO Environmental Improvement & Energy Resources Authority provides a grant for businesses to purchase equipment to use recovered materials, including for composting.

• The Mid-America Regional Council in Kansas City has a grant program for counties, municipalities, and private and public institutions that includes composting.
• St. Louis County has a grant for local municipalities that are trying to divert waste from landfills.
• Several solid waste landfill districts in MO also host their own grant programs that fund composting projects.

References

Columbia (CO). (n.d.). Compost and Mulch Operations. City of Columbia. Retrieved April 23, 2023, from https://www.como.gov/contacts/compost-and-mulch-operations/  

Kansas City Composting (KC 1). (n.d.). STA Certified COMPOST. Kansas City Composting. Retrieved April 23, 2023, from https://www.kccompost.com/compost  

Kansas City Composting (KC 2). (n.d.). Curbside pick-up. Kansas City Composting. Retrieved April 23, 2023, from https://www.kccompost.com/curbside  

Libertelli, C., Platt, B., & Matthews, M. (2023). (rep.). A Growing Movement: 2022 Community Composter Census. Institute for Local Self-Reliance. Retrieved April 14, 2023, from https://cdn.ilsr.org/wp-content/uploads/2023/03/A-Growing-Movement-ILSR-2022-Census-of-Community-Composters.pdf?_ga=2.239483459.1976047449.1681393398-957046353.1681144985&_gl=1*1gdo5nk*_ga*OTU3MDQ2MzUzLjE2ODExNDQ5ODU.*_ga_M3134750WM*MTY4MTQyMDIxNC41LjEuMTY4MTQyMDI1OS4wLjAuMA..  

Lin, L., Shah, A., Keener, H., & Li, Y. (2019). Techno-economic analyses of solid-state anaerobic digestion and composting of yard trimmings. Waste Management, 85, 405–416. https://doi.org/10.1016/j.wasman.2018.12.037  

National Conference of State Legislatures (NCSL). (2022, October 24). Fighting food waste. National Conference of State Legislatures. Retrieved April 24, 2023, from https://www.ncsl.org/agriculture-and-rural-development/fighting-food-waste  

Perennial City Composting (PCC). (n.d.). Perennial city. Perennial City Composting. Retrieved April 23, 2023, from https://compost.perennial.city/  

St. Louis Composting, Inc (STL). (n.d.). Compost. St. Louis Composting, Inc. Retrieved April 23, 2023, from https://store.stlcompost.com/product-category/compost/  

U.S. Environmental Protection Agency (EPA 1). (2022, November 22). Composting At Home. EPA. Retrieved April 14, 2023, from https://www.epa.gov/recycle/composting-home 

U.S. Environmental Protection Agency (EPA 2). (2022, December 3). National Overview: Facts and Figures on Materials, Wastes and Recycling. EPA. Retrieved April 14, 2023, from https://www.epa.gov/facts-and-figures-about-materials-waste-and-recycling/national-overview-facts-and-figures-materials  

U.S. Environmental Protection Agency (EPA 1). (2023, April 4). Reducing the Impact of Wasted Food by Feeding the Soil and Composting. EPA. Retrieved April 14, 2023, from https://www.epa.gov/sustainable-management-food/reducing-impact-wasted-food-feeding-soil-and-composting  

U.S. Environmental Protection Agency (EPA 2). (2023, March 23). Basic Information about Landfill Gas. EPA. Retrieved April 14, 2023, from https://www.epa.gov/lmop/basic-information-about-landfill-gas  

U.S. Environmental Protection Agency (EPA 3). (2023, April 3). Types of Composting and Understanding the Process. EPA. Retrieved April 14, 2023, from https://www.epa.gov/sustainable-management-food/types-composting-and-understanding-process  

U.S. Environmental Protection Agency (EPA 4). (2023, April 12). Funding Opportunities and EPA Programs Related to the Food System. EPA. Retrieved April 14, 2023, from https://www.epa.gov/sustainable-management-food/funding-opportunities-and-epa-programs-related-food-system  

Vergara, S. E., & Silver, W. L. (2019). Greenhouse gas emissions from Windrow composting of organic wastes: Patterns and emissions factors. Environmental Research Letters, 14(12), 124027. https://doi.org/10.1088/1748-9326/ab5262