EPA Updates Data on Anaerobic Digestion

WASHINGTON, D.C. — Based on data submitted by 89 survey respondents to its anaerobic digestion (AD) data collection project, the United States Environmental Protection Agency (EPA) estimates total processing capacity for food waste in 2019 was more than 42.7 million tons. The total amount of food waste processed was more than 17.5 million tons. The total reported amount of non-food waste processed in 2019 was approximately 945,000 tons.

The U.S. EPA in early April released its fourth report produced as part of its anaerobic digestion (AD) data collection project begun in 2014. The latest report is based on a survey completed in 2021 of AD facilities that accept food waste.

Respondents reported on data for three digester types - stand-alone food waste digesters; on-farm digesters that co-digest food waste; and digesters at waste resource recovery facilities (WRRFs) that co-digest food waste.

A total of 99 respondents completed the survey in 2021. Data points are related to process capacity, the amount of food waste processed, the amount of non-food waste process, feedstock types, feedstock sources, the amount of biogas produced, and tipping fees reflect calendar year 2019. The remaining data points, including preprocessing/de-packaging, operational specification, biogas uses, gas cleaning systems, solid digestate uses, and liquid digestate uses reflect circumstances in 2021, according to the EPA.

Based on data submitted by 91 survey respondents (down from 118 for the previous survey), the total amount of biogas produced by all three types of digesters in 2019 was 29,877 standard cubic feet per minute (SCFM), which is equivalent to 93 megawatts (MW) of installed capacity.

The top five food-based feedstock types accepted by AD facilities in the U.S. as of 2019 were beverage processing industry waste; fats, oils and greases (FOG); food processing industry waste; other (not specified); and source-separated organics. The top use of all three digester types was the production of combined-heat-andpower CHP.

The EPA cautions that data on processing capacity, food waste and non-food waste processed, and biogas production are likely underestimated due to the number of operational facilities that did not respond to the survey. The annual surveys will continue through 2025.