H. Lanier Hickman Jr.

Part 8–Composting: Sometimes a Good Idea Does Not Sell

Links to other parts of our series may be found at the end of this article.

The history of MSW composting in the United States is not a pretty story. Composting the MSW organic component is a very good idea that never sold. Early attempts to make composting an important part of solid waste management always failed, primarily for two reasons: the cost of producing compost and the lack of markets for the end product. In addition, the process of composting was not well understood because of a lack of scientific study. More experience and more scientific study have not changed the history of those earlier attempts.

An early Dano installation

Perhaps by accident, and with a lack of understanding, early man and woman practiced composting as part of their agrarian practices. The reuse of animal manure, leaves, decayed fish, and so on as part of farming was nothing more than in situ composting. History tells us that the Pilgrims learned from their neighbors, the Wampanoags, how to use fish heads to improve the growing of maize. Even without any understanding of how composting occurred, we knew that good things happened with composted "stuff."

The American Public Works Association (APWA) reports that the first significant development in composting as an engineering process took place in India in 1925. Sir Albert Howard systematized the process used for centuries by farmers and gardeners to produce humus. It was known as the Indore process because of the country in which Sir Albert’s work was done. It was a simple process consisting of alternating layers of garbage, animal manure, night soil, sewage sludge, and straw, either buried or done in piles. Humus was produced in about six months with two turnings during that time.

The Beccari process was developed and patented in Italy in the early 1920s and consisted of both an anaerobic and an aerobic stage. Several variations of this process occurred in Europe during the late 1920s and early 1930s. The Netherlands, always looking for ways to claim more land from the North Sea, built the first full-scale composting plant in Europe in 1932 using the van Mannen process, a variation of the Indore process that utilized windrows. The Dano and windrow composting systems became quite popular in Europe. The Dano system utilized a rotating drum to start the high-rate composting process. Table 1 describes many of the compost systems used over the decades.

The 1950s

The US did not begin to consider composting as an MSW management method as early as elsewhere in the world. Consequently there were only a few composting plants in the 1950s. A major reason for this lack of composting was an absence of trust for technologies without good engineering and economic data. Another reason was a disposal mentality that did not understand that markets needed development if compost were to be produced from MSW (sounds a good deal like today?).

Serious US studies began in the 1950s, with work at the University of California, Berkeley on aerobic composting (University of California, 1950; 1953). This work was conducted at a pilot plant in Oakland, CA. This work demonstrated that no inoculum¹ was needed to successfully produce compost by the windrow method. At Michigan State University, work was done that helped document such variables as pH, moisture, and temperature (Schulze, 1961). Out of this work came the "modified" compost process, which utilized forced air as a part of the control of the composting process (see Figure 1). A modified, silo-type, eight-level Earp-Thomas digester was used in their studies.

In 1953, the US Public Health Service (USPHS) began two research projects on composting. One plant was located in Savannah, GA, and the other in Chandler, AZ. The Savannah work was primarily laboratory scale, and the Chandler project actually developed and operated a 70-ton-per-week experimental plant that used aeration and bin and windrow composting. Both projects developed substantial data and information on the costs and processes for making compost.

Click here for an enlarged view

John Wiley and George Pierce of the USPHS published widely on the results of this work (Wiley and Pearce, 1955; Wiley, 1958). Figure 2 is a schematic of the Phoenix, AZ, facility.

The 1960s-1970s

The passage of the Solid Waste Disposal Act in 1965 resulted in increased funding for the USPHS. As a result, the USPHS initiated two MSW composting projects to study and document the economic and technical feasibility of composting MSW.

The Johnson City, TN, project was a windrow compost plant owned jointly by the Tennessee Valley Authority and the USPHS. Its principal purpose involved co-composting MSW and sewage sludge and studying the resultant compost as a material to benefit soils. The USPHS provided the project engineers for the plant to oversee both the operations and conduct the research on soil-quality enhancement from the application of MSW/sewage-sludge compost. The first project engineer at Johnson City was John Wiley. Carlton Wiles became the project officer in the latter years of the 1960s and served until the project closed in the early 1970s.

The companion project to Johnson City was Gainesville, FL. This MSW composting plant used the Metro Conversion process (a high-rate composting process [see Table 1]).

Similar studies to those in Johnson City began in 1968. John Ruf was the project engineer for this USPHS study. The results of the research work from these two USPHS/USEPA projects were published by USEPA (USEPA, 1971). In addition to the findings from the projects, the report included descriptions and observations of various composting processes in use internationally, as well as the status of composting internationally and in the US. Twenty-six plants in some 12 countries were noted. Table 1 lists the various compost processes used in these plants. In the US, 18 plants were funded and built between 1951 and 1969. Table 2 lists the locations, principal characteristics, and status of each of those plants at the time of the report. Seven of the plants listed had closed by 1971. The report cites operations and financial difficulties as the major factors in the closings.

It should be noted that windrowing is, in almost all cases, a part of the composting process, even with high-rate composting. Windrows are used as a final stage for either active composting or aging, or both. Aeration with windrowing can occur by simply turning the windrow or by aeration of static-pile windrows. Figure 1 is a schematic of a static-pile forced-air composting process.

The findings from the observations taken from Johnson City and Gainesville and the surveys of MSW composting practices in the US and overseas were:

1. Composting of MSW was a sanitary process.
2. Properly managed windrows or high-rate, enclosed processes will produce a safe product for agriculture or gardening use, but it is not a fertilizer.
3. Processes that existed at the time of the study would permit recycling of organic wastes to the soil without significant pollution to water or land resources.
4. The high cost of producing compost was not offset by revenues from sales.
5. The high cost of producing compost would not let it compete economically with current land disposal and combustion processes in use at the time of the study.
6. As environmental regulations for landfills and incinerators increase, the costs of these two methods would increase. This would result in composting becoming more economically viable.

It is interesting to note that, according to this report, operational problems at MSW composting plants, which had been a problem in the past decade, did not appear to be an issue in the 1960s-1970s.

1980s to Today

The last of the plants listed in Table 2, Altoona, PA, closed in the mid-1980s. From the late 1960s to the closing of Altoona, many reasons can be cited for the closures, including odor complaints, poor product quality, lack of markets, and poor economics. However, MSW composting did not die with the closing of Altoona. With renewed interest in recycling, diversion rates, and recycling goals in the 1980s came measures to begin separation of the MSW stream into a number of solid wastestreams. These measures brought about a reawakening of interest in composting as a method of integrated solid waste management. But would the idea succeed this time?

SWANA, with funding from USEPA, reported on the status of MSW composting in 1995 (SWANA, 1995). Findings of that effort included the following: By 1994 there were 17 operating compost facilities in the US. Thirteen were composting MSW and four were composting source-separated MSW organics. Table 3 summarizes the locations, processes, and capacities of these 17 plants.

While plants opened in the 1980s-1990s, plants also closed. Table 4 summarizes plants that shut down during the 1990s. Reasons for closing varied, but odors and economics were the dominant reasons.

An Earp-Thomas composting plant

The Earp-Thomas digester used in the Michigan State studies

Windrow-turning machine

The SWANA study provided information on composting technologies, economics, and operating experiences during the 1980s-1990s. A number of lessons learned were noted:

1. Composting MSW generates odors, but odors can be managed with proper design and operation.
2. Careful attention to the preparation of MSW as a feedstock and monitoring and control of the composting process are essential to manufacturing a marketable product.
3. Product finishing received greater attention than in the past; the results of more attention to finishing were a more marketable product and therefore better market opportunities.
4. The loss of waste flow control affected the economic viability of composting as part of integrated solid waste management.
5. The economic viability of MSW compost facilities was such that they cannot withstand dramatic shifts in technology requirements or institutional arrangements.
6. Siting an MSW compost facility was like siting any other MSW facility: difficult, if not impossible.
7. Manufacturing compost to meet stringent standards was very difficult to do. Even when this was accomplished, markets remain a major problem.

Comparing these lessons to the ones noted by the USEPA/USPHS work in the 1960s and 1970s, the problems of markets remain the essential barrier to composting MSW. On the other hand, more stringent regulations of landfill and incinerators have not opened up markets for MSW compost, as USEPA/USPHS thought. If MSW composting is ever to become an idea realized, the lessons learned during the 1980s and 1990s must be fully applied. Half-baked approaches with a "field of dreams" view that composing should be done because it is a good "thing" and compost is good "stuff" will not work. Means must be found to create the markets for what is indeed good "stuff." Then the idea of composting will be one whose time has finally arrived.

Notes

There is always a certain segment of people and organizations involved in the composting of organics that believe some magic bug must be used to make composting work. Indeed, there are many magic bugs involved in making compost, but charlatans selling an inoculum are not necessary. Mother Nature does a first-rate job of providing all of the inoculum needed at no costs.

References

APWA. Municipal Refuse Disposal. American Public Works Association, Chicago, IL. 1961.

SWANA. Municipal Solid Waste Composting: A Status Report. SWANA Publication #GR-REC 0250. Solid Waste Association of North America, Silver Spring, MD. 1995.

Hickman Jr., H. Lanier. The Principles of Integrated Solid Waste Management. American Academy of Environmental Engineers, Annapolis, MD. 1999.

Schulze, K.L. Aerobic Decomposition of Organic Waste Materials. Final Report. Project RG-4180 (C5R1). US Public Health Service, Michigan State University. April 1961.

University of California. "Composting for Disposal of Organic Refuse." Sanitary Engineering Research Project. Technical Bulletin No. 1, Series 37. UC Berkeley, CA. July 1950.

University of California. "Reclamation of Municipal Refuse by Composting." Sanitary Engineering Research Project. Technical Bulletin No. 9, Series 37. UC Berkeley, CA. June 1953.

USEPA. Composting of Municipal Solid Waste in the United States. US Environmental Protection Agency, Washington, DC. 1971.

Wiley, John S. and George W. Pearce. "A Preliminary Study of High-Rate Composting." Proceedings, Vol. 81, Separate No. 846. ASCE, New York, NY. December 1955.

Wiley, John S. Composting of Organic Wastes — An Annotated Bibliography. USPHS, CDC, Savannah, GA. February 1958.

H. Lanier Hickman Jr., P.E., D.E.E., is a member of MSW Management’s Editorial Advisory Board.

To read the other parts in this feature please click on the relevant links below:

Part 1: Introducing the Pioneers
Part 2: Of Mosquitoes, Flies, Rats, Swine, and Smoke
Part 3: The Sanitary Landfill
Part 4: Building a National Movement
Part 5a: Building an Infrastructure
Part 5b: Building an Infrastructure
Part 6: Collecting Solid Waste/No Longer Beasts of Burden
Part 7a: Landfill Gas Odors/Fires, Explosions, and Kilowatts
Part 7b: Landfill Gas - An Asset, Not a Liability
Part 8: Composting: Sometimes a Good Idea Does Not Sell
Part 9a: The Awakening of Waste-to-Energy in the US