The benefits of composting are well documented. Compost is a valuable soil conditioner. It adds needed organic matter, sequesters carbon, improves plant growth, conserves water, reduces reliance on chemical pesticides and fertilizers, and helps prevent nutrient runoff and erosion. Composting also reduces the volume of materials that might otherwise be disposed in landfills or trash incinerators, and repurposes these materials through recycling. It is a place-based industry, which cannot be outsourced abroad. Thus, advancing composting and compost use in the U.S. is a key sustainability strategy to create jobs, protect watersheds, reduce climate impacts, improve soil vitality, and build resilient local economies.
With all these benefits, why aren’t we composting more? How can we generate and use more compost to sequester carbon in soil and improve soil structure and fertility? Where can the compost come from? What kinds of systems are the most effective? What types should be promoted? What are the threats to expanding composting? What are its limitations? What infrastructure and policies are needed to advance composting? How do we do implement these?
To answer these questions, the Institute for Local Self-Reliance has coauthored a new report, State of Composting in the U.S.: What, Why, Where & How, with Nora Goldstein (BioCycle), Craig Coker (Coker Composting & Consulting) and Sally Brown (University of Washington). The report, available for download at ilsr.org/initiatives/composting, explains what composting is and why it is important; summarizes model programs, technologies and systems; and provides a national and state-by-state snapshot of activities, infrastructure needed, and policy opportunities. It concludes with recommendations on how to grow composting in the U.S.
This article provides highlights from State of Composting in the U.S., specifically new data on job creation benefits of composting and compost use, updated information on state infrastructure and programs, and key policies for advancing composting.
For the Soil
Improving soil and protecting watersheds are two key drivers of why we need more composting. One-third of the world’s arable land has been lost to soil erosion and continues to be lost at an alarming rate (Zang and Wang, 2006). In the U.S., 99 million acres (28% of all cropland) are eroding above soil tolerance rates, meaning the long-term productivity of the soil cannot be maintained and new soil is not adequately replacing lost soil (NRCS, 2007). Erosion reduces the ability of soil to store water and support plant growth. Amending soil with compost improves soil quality and structure, increases water retention, reduces chemical needs, and cuts nonpoint source pollution.
Like reuse and recycling, composting offers direct development opportunities for communities. Whether on a per-ton basis or on a per-dollar-capital investment basis, composting sustains more jobs than other waste handling options such as landfilling and incineration. But unlike linear disposal systems, composting is ultimately a manufacturing enterprise that produces a value-added product for multiple end markets where jobs are sustained in each phase of the organics recovery cycle. In addition to the direct jobs at composting facilities, use of compost supports new green enterprises and additional jobs. Most of the end markets for compost tend to be regional, if not local. Each recycling step a community takes locally means more jobs, more business expenditures on supplies and services, and more money circulating in the local economy through spending and tax payments.
More than 15 years ago, ILSR conducted extensive research on the jobs sustained by reuse, recycling and composting. On a per-ton basis, the research found that composting sustains four times the number of jobs as landfill or incinerator disposal (Platt and Seldman, 2000). While a few studies have since been released evaluating jobs and recycling, ILSR’s per-ton job factors have not been updated and little data exists documenting the jobs through composting. In 2013, ILSR evaluated the current and potential composting-related jobs in Maryland. This study, Pay Dirt: Composting in Maryland to Reduce Waste, Create Jobs & Protect the Bay, found:
- Composting (including mulching and natural wood waste recycling) operations in Maryland already sustain more total jobs than the state’s three trash incinerators, which handle almost twice as much tonnage.
- On a per-ton basis, composting in Maryland employs two times more workers than landfilling, and four times more than the state’s trash incinerators.
- On a per-dollar-capital investment basis, for every $10 million invested, composting facilities in Maryland support twice as many jobs as landfills and 17 more jobs than incinerators.
- An entire new industry of contractors who use compost and compost-based products for green infrastructure has emerged, presenting an opportunity to establish a new made-in-America industrial sector, creating even more jobs.
- Utilizing 10,000 tons of finished compost annually in green infrastructure can sustain one new business. For every 10,000 tons of compost used annually by these businesses, 18 full-time equivalent jobs can be sustained.
Table 1 presents employment data for 13 companies, spanning Maryland to California, that specialize in using compost for green infrastructure (e.g., bioswales, green roofs, green streets, rain gardens). These 13 companies together employ 70 workers involved with using approximately 38,000 tons per year of compost (84,000 cubic yards of material). In other words, they sustain ~18 positions per 10,000 tons of compost they use each year (or 6 positions per 10,000 tons of raw materials composted).
Table 2 compares job creation benefits of both composting and compost use compared to disposal options in Maryland. When taking into account the potential jobs that could be sustained by utilizing compost in-state for green infrastructure, on a per-ton basis, composting and compost use would sustain five times more jobs than landfilling and nine times more jobs than incineration.
Based on ILSR’s research for Maryland, for every one million tons of organic materials composted (and not disposed) at a mix of small, medium and large facilities — with the resulting compost used in-state — almost 1,400 new full-time equivalent jobs could potentially be supported, paying wages ranging from $23 million to $57 million. In contrast, when disposed in Maryland’s landfills and incinerators, this tonnage only supports 120 to 220 jobs (Table 3).
What is the State of Composting in the U.S.? In a nutshell, municipal and county governments, as well as private food scrap generators, increasingly recognize the importance of diverting yard trimmings and food scraps from disposal to reach recycling goals and manage solid waste handling costs. However, while recovery of yard trimmings is well established, infrastructure for composting food scraps lags behind.
Data collection methods used by BioCycle are explained in an accompanying sidebar. Of the 4,914 composting operations identified in the U.S. for this study, about 71 percent compost only yard trimmings (based on 44 states reporting.) The totals are divided as follows (Table 4): Yard trimmings: 3,453; Food waste: 347; Mixed organics (combinations of various organic waste streams): 87; Mixed waste composting (unsorted solid waste): 11; Biosolids: 238; Composting on site at institutions: 337; Composting on site on farms/agricultural operations: 400; Miscellaneous: 41. Figure 1 shows a breakdown by type. Food scrap recovery is slowly growing. More than 180 communities have instituted residential food scrap collection programs, up from only a handful a decade ago. Countless supermarkets, schools, restaurants and other businesses and institutions are also source separating their food scraps for composting. But the current infrastructure remains inadequate.
State organics recycling officials contacted as part of this project were asked for the total tons of organics diverted to composting and to tally the number of composting facilities in their state by volume of material processed. Thirty-three of the 44 responding states were able to provide a quantity — a total of 19,431,687 tons of organics diverted to composting (Table 5). The organic waste streams primarily consist of yard trimmings, food scraps, biosolids and some agricultural waste streams, including manure. Of the states reporting, California had the highest composting tonnage in 2012 (5.9 million tons); Florida had the second highest (1.5 million tons), followed by Iowa (1.3 million tons), Washington State (1.2 million tons) and New York (1.0 million tons).
State officials contacted were asked to tally the number of composting facilities in their state by volume of material processed (i.e., processing capacity). Three capacity ranges were provided:20,000 tons/year. A response to this requested breakdown was provided by 31 states: 72% of the 3,285 composting facilities (2,354) in those 31 states are composting less than 5,000 tons/year of materials (Table 5). There are 713 facilities in the 5,000 to 20,000 tons/year range. Only 218 facilities are composting more than 20,000 tons/year. States responding to this inquiry include heavily populated states such as California, Florida, Massachusetts, New Jersey, New York, Ohio, Virginia and Washington.
As shown in Table 5, 27 of those 31 states also reported the total amount of organics diverted to composting in 2012. In total, those 27 states diverted 16,321,000 tons of organics to composting at 3,166 facilities (the total of 3,285 less the 119 facilities in the four states that did not provide a total amount of organics diverted to composting). That is an average of 5,155 tons/facility/year. This is far too small. To achieve higher levels of composting in the U.S., more processing capacity will be needed.