Anaerobic Digestion Facilities Processing Food Waste in the U.S. (2022 & 2023)

On this page:

• Background and Survey Process
• Survey Responses, Operational Dates, and Status
• Food Waste Processing
• Non-Food Feedstock Processing and Available Capacity
• Tipping Fees
• Biogas Production and Use
• Operational Specifications and Pre-processing Activities
• Digestate Uses
• Annual Survey Results
• Related Links and Resources

Background and Survey Process

In 2014, EPA began building a dataset of names and locations of anaerobic digestion facilities processing food waste to better understand the practice and prevalence of food waste digestion in the U.S. EPA recognized that data showing the feasibility of using anaerobic digestion to process food waste is important for states, communities, and others working to divert food waste from landfills and combustion facilities. In December 2016, EPA was granted the authority to survey digesters annually, and EPA renewed that authority until 2025. This is the final set of survey data that will be published. Learn more about the objectives, history, and previous survey results on the Anaerobic Digestion Data Collection Project homepage.

The data presented below are from the sixth and final round of data collection, which was completed in 2024. The data are from three types of anaerobic digestion facilities:

1. Stand-alone food waste digesters.
2. On-farm digesters that co-digest food waste.
3. Digesters at water resource recovery facilities that co-digest food waste.

Learn about different types of anaerobic digesters.

The survey of anaerobic digestion facilities completed in 2024 collected the following data for 2022 and 2023:

• The amount of food waste processed.
• The amount of non-food waste processed.
• Feedstock types and sources. 
• The amount of biogas produced.
• Information about tipping fees.

Other data collected reflect circumstances at the time of the survey, including operational dates and operational status, operational specifications, biogas use, and digestate treatment and use. You can access the complete set of survey questions in the Related Links and Resources section of this page.

All data were voluntarily submitted by survey respondents and were aggregated and checked for quality before publication. You can find data from previous years, going back to 2015, in reports on the Anaerobic Digestion Data Collection Project homepage. EPA maintains a list of anaerobic digestion facilities in the U.S. – those that process food waste and those that do not – that you can download from the Excess Food Opportunities Map.

Survey Responses, Operational Dates, and Status

EPA shared the 2024 survey directly with 313 facilities believed to be operational and for which EPA had contact information. EPA also kept the link to the survey open on the Anaerobic Digestion website through August 5, 2024. EPA received responses from 65 operational and two non-operational facilities across 29 states. The two non-operational facilities were in the construction stage, or temporarily shut down at the time of the survey. Not all facilities responded to all questions.

Number of Anaerobic Digestion Facilities Processing Food Waste Surveyed in 2024 and Response Rate

The states with the most operational anaerobic digesters returning survey responses were California (13 responses), Pennsylvania (8), Massachusetts (7), and New York (6). The numbers presented below for food waste processing and biogas production underestimate actual food waste processed and biogas produced in 2022 and 2023 because not all operational anaerobic digestion facilities processing food waste in the U.S. responded to the survey.

The survey asked facilities for their current operational status and the year they began operation. The table below describes in which decade responding facilities came online. Of the 65 survey respondents for this question, the largest number (30) started operations in the 2010s.

Food Waste Processing

Of the 65 facilities that were operational at the time of survey, five did not process food waste in 2022 and 2023. For the purposes of the survey, food waste includes the following categories:

• Beverage processing industry waste (e.g., liquid wastes from brewing beer).
• Fats, oils and greases (e.g., used cooking oils).
• Food processing industry waste.
• Food service waste, pre- and post-consumer (e.g., kitchen scraps or uneaten plate waste).
• Fruits/vegetative wastes.
• Retail food waste (e.g., unsold food from grocery stores).
• Slaughterhouse wastes.
• Source-separated commercial, institutional or residential organic wastes.
• Other food waste.

Where facilities reported their food waste processing amounts in gallons, EPA used conversion factors appropriate for each feedstock to convert gallons to tonnages before calculating the total amount of food waste processed each year. Based on data submitted by 56 survey respondents, and EPA’s conversions where necessary, the total amount of food waste processed in all three digester types in 2022 was over 16 million tons. In 2023, 58 respondents processed over 7.6 million tons of food waste. The difference in reported totals is largely attributable to the amounts of waste from the beverage industry that were processed in 2022 and 2023.

Beverage processing waste at stand-alone digesters comprised the majority of food waste processed in 2022 and 2023. This is consistent with previous years of survey data, and is due to several factors. First, beverage processing waste has a density similar to water, whereas source-separated organics, for example, contain less moisture and weigh less. Accordingly, a volume – in gallons – of beverage waste will convert to a greater tonnage than the same volume of source-separated organics. Second, most anaerobic digesters in the U.S. are wet systems, designed to process high-moisture feedstocks, such as process water, wash water, and other liquids that contain organic solids. Finally, nearly half of the stand-alone facilities responding to the 2024 survey are co-located at breweries and solely dedicated to processing brewery waste. In 2023 these stand-alone digesters reported processing less than half of their processing totals from 2022, resulting in the unexpected decrease in total processing. The use of anaerobic digestion systems at breweries is well-established.

The table below describes the amounts of food waste processed in 2022 and 2023 with and without beverage processing waste included, for comparison. Charts below describe food waste processed in 2022 and 2023 on two scales to better illustrate the influence of beverage processing waste on the total annual tonnages. Tonnages are wet U.S. tons.

Total Amount of Food Waste Processed in 2022 and 2023 by Survey Respondents

In both 2022 and 2023, the top five sources of food waste processed via anaerobic digestion were as follows (in order of most to least tons):

• Industrial – manufacturing and processing.
• Commercial – food retail/wholesale.
• Commercial – restaurants and food services.
• Other – a combination of commercial, residential, institutional, and industrial that could not be disaggregated by the facility.
• Industrial (other).

Industrial sources were reported in significantly larger quantities than other sources. Manufacturing and processing accounted for over 14 million, and 6 million tons of waste in 2022 and 2023 respectively. The commercial sector was reported as processing over 400,000 tons (retail and wholesale, both 2022 and 2023), and 200,000 tons (restaurants and food service, both 2022 and 2023). The two other sources listed, other and industrial (other), reported between 40,000 and 90,000 tons of processing for the data years. Outside the top five sources there was a significant decrease in reported tonnages with all other sources reporting less than 200 tons.

In 2022 and 2023, the top six types of food waste processed from most to least were as follows (in order of most to least tons):

• Beverage processing industry waste.
• Food processing industry waste in 2022; fats, oils, and greases in 2023.
• Fats, oils and greases in 2022; food processing industry waste in 2023.
• Source-separated commercial, institutional, or residential organic waste.
• Process and/or wash water.
• Food service waste, pre- and post-consumer.

The following charts describe the top six types of food waste processed in 2022 and 2023 on two scales. Access exact amounts, types, and sources of food waste processed in detailed matrix tables on our Supplemental Data webpage.

Non-Food Feedstock Processing and Available Capacity

Most anaerobic digestion facilities co-digest food waste with other organic waste. Anaerobic digesters at water resource recovery facilities (also known as wastewater treatment plants) are primarily dedicated to digesting wastewater solids (also known as sewage sludge). Anaerobic digesters on farms are primarily dedicated to processing animal manure. Anaerobic digestion decreases the volume of organic materials, which is beneficial for managing large waste streams such as wastewater solids, manure and – increasingly – food waste.

Eight WRRFs reported processing non-food waste feedstocks in addition to wastewater solids generated on-site. Those feedstocks were wastewater solids from other WRRFs, septage, and non-food waste from the industrial sector (e.g., B-grease renderings from making glycerin). Two stand-alone anaerobic digestion facilities reported processing mixed yard waste as their non-food waste feedstock. No other non-food feedstocks were reported by stand-alone facilities. All farm anaerobic digestion facilities reported processing manure as a non-food feedstock; however, only one farm anaerobic digestion facility reported accepting animal manures not generated on-site.

At the time of survey, 55% of the 44 respondents reported having some available capacity to process feedstocks from off-site sources. The total available capacity at anaerobic digestion facilities is difficult to pinpoint, given that facilities calculate capacity use through a variety of methods. Also, various factors may impact the feasibility for digesters to process additional food waste specifically, such as:

• Availability of additional quantities of non-food feedstocks, including manure at on-farm digesters and wastewater solids at WRRFs.
• Accessibility of food waste (e.g., proximity to the digester).
• Available pre-processing technologies.
• Optimal mix of feedstocks for efficient digestion and biogas production.

Tipping Fees

Of 60 respondents, 80% reported collecting tipping fees, which are fees paid to the anaerobic digestion facility by waste haulers or generators to process food waste and other feedstocks. 18 facilities shared data on tipping fees collected in 2022 and 2023. Based on those responses, in 2022 the median tipping fee was $20.63 per ton and the average was $30.27 per ton. In 2023, the median tipping fee was $22.23 per ton and the average was $32.27 per ton. Four facilities reported setting base rates of $0.01, $0.06, $0.09, and $0.10 per gallon of feedstock. Several facilities charge different rates depending on the quality, type, or source of feedstock. For example, the facility might set fees higher if food waste needs to be de-packaged, they might charge grease haulers but not source-separated food waste haulers, or they may charge to tip food waste but not manure.

Biogas Production and Use

Based on the data reported, the combined total amount of biogas produced from food waste and non-food feedstocks by respondents of all digester types was 18,926 standard cubic feet per minute (SCFM) in 2022 and 19,711 SCFM in 2023. 50 respondents provided usable data for 2022 and 53 for 2023.

Summary of Biogas Data Reported by Survey Respondents (2022 & 2023)

*Facility operators reported values in SCFM, SCFD or SCFY, which were converted to SCFM by EPA, and summed to get annual totals. Equivalencies in MW, kWh/yr and number of homes powered were calculated using the Landfill Methane Outreach Program interactive conversion tool.

Facilities often scrub biogas to remove unwanted components before they use it. Of 55 responding facilities, 84% reported using a gas cleaning system at the time of survey. The most common constituents removed were hydrogen sulfide, sulfur, and moisture.

Facilities use biogas to produce heat and electricity or convert it into renewable natural gas. Facilities can use biogas and the resulting energy onsite, sell energy to the grid or pump upgraded biogas into a pipeline. Only five out of 62 respondents reported selling the biogas they produced and not using any onsite. The most common use of biogas for WRRFs and farms at the time of survey was to produce both heat and electricity through combined heat and power systems. The second-most common use for WRRFs was as fuel for boilers and furnaces to heat the digesters. For stand-alone facilities, the most common use of biogas was as fuel for boilers and furnaces to heat other spaces (i.e., not the digesters).

When a facility cannot use or sell all the biogas it produces, they flare the excess biogas, which is a common practice. Out of 62 respondents, 84% reported flaring some or all the biogas they produced. Two facilities reported only flaring biogas and not putting any to onsite or offsite use.

Operational Specifications and Pre-processing Activities

As in previous surveys, results show that most digesters are wet and mesophilic systems (52 out of 60). For farms, WRRFs, and stand-alone facilities at the time of survey, the most common pre-processing activity was screening or sorting. Stand-alone facilities also commonly used pH adjustment in processing their feedstocks. 21 facilities (five WRRFs, five stand-alone, and 11 farm) reported doing manual or mechanized de-packaging.

Digestate Uses

Digestate is often, but not always, separated into liquid and solid portions, which are then treated and managed separately.

The top uses of solid digestate by digester type in the 2024 survey were:

• Stand-Alone Digesters: composted into a reusable or salable product, and de-watered or dried then land applied. Other reported uses include turning digestate into animal bedding or cattle feed or selling digestate to help start up other digesters.
• On-Farm Co-Digesters: composted into a reusable or salable product. Other respondents also reported de-watering or drying then land applying the digestates, or land applying in slurry form.
• Co-Digestion Facilities at WRRFs: de-watered then land applied and landfilled. Other reported uses include land applying as-is with no dewatering and composting into a reusable or salable product.

The top uses of liquid digestate by digester type in the 2023 survey were:

• Stand-Alone Digesters: discharged to a wastewater treatment plant and reused as fertilizer via land application.
• On-Farm Co-Digesters: reused as fertilizer via land application.
• Co-Digestion Facilities at WRRFs: discharged to a wastewater treatment plant (i.e., returned to the beginning of the wastewater treatment system) and recirculated through the digester.

Annual Survey Results

The table below provides a brief snapshot of the annual results for amounts of food waste processed and biogas produced as well as survey response rates since the start of EPA’s Anaerobic Digestion Data Collection Project.

Critical Data Points Reported by Survey Respondents for Years 2015 - 2021

*2019 was the first year for which the granularity of data collected allowed specific densities to be assigned to specific feedstocks. For example, beverage processing industry waste was assigned the density of water (8.34 lb/gallon), higher than the density of source-separated organics and other similar food wastes (3.8 lb/gallon).

The number of identified anaerobic digestion facilities processing food waste in the U.S. has increased steadily since the beginning of the Anaerobic Digestion Data Collection Project, from 154 in 2017 to 313 in 2024 (and 313 is likely an undercount). Conversely, the survey response rate has decreased steadily. Each year, the specific facilities that report and the number of facilities that respond to each survey question varies. So, it is not recommended to analyze year-over-year trends in these data.

The anaerobic digestion industry has seen dramatic growth since 2015. When properly permitted and operated, anaerobic digestion projects can provide economic, health, and environmental co-benefits to surrounding communities while recovering energy and nutrients from organic materials. However, there are challenges with anaerobic digestion, as with any food waste management technology, and EPA encourages communities to consider lifecycle and other environmental impacts when deciding how to manage wasted food and other organic materials.

Related Links and Resources

• View the questions from the 2024 Survey:  EPA 2024 Anaerobic Digestion Survey (pdf) (238.98 KB) .
• Download reports from previous years from the Anaerobic Digestion Data Collection Project webpage.
• View and download EPA’s dataset of anaerobic digestion facilities in the U.S. from the Excess Food Opportunities Map.
• Check out the Wasted Food Scale to learn about food waste management pathways.
• View American Biogas Council’s new Biogas State Profiles for all 50 states.
• Learn more about anaerobic digestion on farms from the EPA AgSTAR program.
• Learn more about emerging issues in food waste management and environmental impacts of food waste in the U.S. through EPA's Food Waste Research.
• Get more data on food waste in the U.S. from EPA's Facts and Figures and Wasted Food Report.