Composting State of Practice: Results From a National Operations Survey

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Compost production is growing in the United States as regulations in some parts of the country aim to keep organics out of landfills, and society is more conscious of the climate implications of their consumption and disposal habits. Despite this production growth, nationally aggregated information on compost production, the distribution and characteristics of compost facilities, and compost operations is limited. This report aims to fill in some of these gaps and provide a national picture of composting operations in the United States. Trends were aggregated from information provided by over 300 respondents to a survey distributed to compost facilities between 2021 and 2022. Respondents ranged from small, educational community compost sites to highly technical sites processing several tons of organics daily. They provided information about their facilities, throughput, and operations.

There has been clear growth of the compost industry through the development of new, larger facilities and expansion of existing facilities. Overall, the number of facilities increased by 55% between 2016 and 2021, which was outpaced by an 83% increase in tonnage processed by respondents. Similar growth was also observed from 2016 to 2019 with a 39% increase in the number of active facilities and a 57% increase in the tonnage processed. On a facility basis, all facility types except windrows had an increase in total tonnage of organics processed in 2019 and 2021 from 2016. Windrow facilities did see an increase in tonnage processed 2019, but this leveled off in 2021.

Regional differences in facility characteristics were also observed. Despite having about half the number of facilities represented as the Northeast, the Pacific and the Southeast regions managed about 40% and 30% of organics in 2021, respectively. In comparison, the Northeast had the greatest number of facilities reporting, but processed just under 10% of organics in 2021.

The survey also provided information about trends in composting operations. Windrows were the most common composting method with 42% of facilities reporting use of this method. Twenty-two percent of facilities use multiple composting methods. This was the second most common method and the method responsible for processing more organic waste and producing more compost than any of the single-method facilities. Facilities also reported on the types of feedstocks that they accept with about a third of facilities only accepting a single feedstock. Yard waste was the most commonly accepted feedstock with just under 80% of facilities accepting this feedstock and food waste was second with 51% of facilities accepting food waste. Sixty percent of facilities reported that these feedstocks are collected from 25 miles away or less.

Compost facilities are complex businesses relying on different revenue sources depending on their size. The responses indicated that large facilities rely on tipping fees for 80% of their revenue, on average, while smaller facilities generate more revenue from product sales and “other” revenue streams. In terms of markets, approximately one-third of the compost produced by respondents is sold for agricultural purposes, while landscaping was the most common market for a producer to sell to with 68% of facilities selling to this market. The results also suggest there are some economies of scale that occur with employment and equipment as a facility increases in size. Large facilities require about 2.9 employees per 10,000 tons compared to 12.4 employees for smaller faciResults lities. Similarly for equipment there are economies of scale, on average large facilities have 3 more pieces of equipment than medium facilities compared to an increase of 10 pieces of equipment from small to medium sized facilities.

Overall, the results of this study provide a snapshot into current composting facility operations. As the industry continues to grow and shift due to changing regulations and policies, regular collection of information is needed to provide long-term perspectives on the compost industry.