Reports from pilot projects on solid waste management often end up in the recycling bin themselves-or, at best, gathering dust on shelves. But the effects of a report on the composting of household garbage, as carried on in a pilot project in Connecticut four years ago, are still moving outward in ever-expanding circles. It's an endeavor whose results have made it a standard in the field.
"That project was very successful," says Martin Simson, Director of Administration for the Composting Council in Alexandria, VA, which monitors the progress of various large-scale composting efforts nationwide. "Now this area of composting, with food scraps from all kinds of sources, has been really exploding." There are now at least 19 sites around the country where household and business garbage of various types is being turned into rich compost for use as a soil amendment in gardens, nurseries and municipal plantings.
The Connecticut project, carried on in Fairfield and Greenwich in 1992, was a wedding of private industry and an environmental group, and like many good marriages, it began with an argument.
"I used to meet Bruce Jones, a composting specialist for Procter & Gamble, at meetings of the EPA's Recycling Advisory Council," Jan Beyea, Chief Scientist for the Audubon Society, told a reporter for the society's publication. "We had some fierce debates over the issue. Then one day we said, 'Why fight all the time? Let's do something positive.' "
What they did was try to find out how much of the organic detritus generated in the typical household could be turned into useful compost, thus taking a bite out of the municipal waste stream, already mercifully depleted by nationwide efforts to recycle such materials as glass, metal and newsprint.
Why Procter & Gamble? "Look under the kitchen sink and the bathroom sink in the average household and you'll see about 20 Procter & Gamble products," said Margaret Conditt, Senior Scientist for Environmental Public Policy at Procter & Gamble in Cincinnati, OH. "That's a lot of packaging thrown away." One of those products is Pampers; disposable diapers are used on about 85% of American babies-a favorite symbol of environmental profligacy for purists.
Audubon's local network of chapters came into play, and the project-with Dr. Conditt as project manager-started up in Connecticut in March 1992. The Greenwich Audubon Society recruited some 500 families in Greenwich and Fairfield, who agreed to separate compostables such as food garbage, cardboard packaging, and disposable diapers, into paper "wet bags" lined with biodegradable cellophane. For a month, these bags were picked up by regular trash haulers and taken to the municipal composting facility, already in use for rendering municipal sewage sludge into compost. Several local McDonald's restaurants got involved, adding soggy coffee grounds to the mix.
Such composting facilities are vast halls, sometimes compared to bowling alleys or skating rinks, containing (in Fairfield's case) six 220-foot-long bays. Compostable materials such as dewatered sewage sludge-or in the case of the pilot project, things such as shredded carrot tops, Kleenex, diapers and pizza boxes-is dumped into one end of a bay. The material has to be moved along the bay to come out the other end as compost, and it has to be turned, just as a backyard compost pile has to be turned. This is done with a mixer-agitator, a huge machine that moves along the top of the bay on tracks. Like a vast rototiller, it reaches 5 feet down into the steaming mass, turns it over and moves it 12 feet toward the finishing end of the bay each day. The total composting process takes about three weeks.
At this point a well-known state institution-The Connecticut Agricultural Experiment Station-lent a hand, though the station had already been involved in designing the research. (Other participants were the Town of Fairfield, International Process Systems and Waste Management of North America.) The Experiment Station tested the material all along the way, using physical, chemical and biological parameters to determine its quality and maturity. As the bacteria that carry on the composting process did their work, "it broke down amazingly fast," says Charles Frink, Chief Soil Chemist Emeritus at the Experiment Station.
The Station analyzed the compost at the end of the process to determine whether pathogens were present (in the composting facility, material is kept at 55° C. for three days in order to kill these) and for metals and other inorganic elements. These were found to be well below EPA standards for the unlimited application of sewage sludge to agricultural land. Further analyses at Woods End Research Laboratory in Maine found high levels of nutrients (nitrogen, phosphorus and potassium), low levels of metals and no pathogens.
Then the Station used the compost for what compost is supposed to be used for: growing plants. It conducted growth studies in a field application with tomato plants and a container application of a flowering perennial. Tomato plants were grown in 10-by-10-foot field plots to which were added zero, 25 and 50 tons of compost per acre; the 50-ton-per-acre plots showed a 38% greater yield of tomatoes than the zero-ton control plots. Compost used in a potting soil mixture produced hearty, flowering black-eyed Susans.
Another impressive statistic was the decrease in garbage carried to landfills from the homes that participated in the project. These homes already contributed about 40% of their waste to the recycling of plastic, paper and glass; composting took care of another 30%, meaning that 70% of the households' waste was "diverted" from the waste stream.
"The results were extremely encouraging," said Dr. Conditt. "We were lucky to be working in a community like Connecticut, very environmentally aware, with source separation already in effect."
Since then, she said, joint municipal solid waste composting projects-known in the trade as MSW composting-involving both Procter & Gamble and the Audubon Society have blossomed like the Fairfield black-eyed Susans. The Composting Council counts 19 permanent installations throughout the country. All compost municipal solid wastes; some mix it with yard waste, milling residue, grocery and restaurant waste and sewage sludge. The primary use of composted sewage sludge to date in Connecticut has been for landfill cover. The Connecticut Department of Environmental Protection currently permits the one-time use of composted sewage sludge for topsoil blending on a case-by-case basis. Composted municipal wastes would be permitted in a similar fashion.
A 1996 food composting survey conducted by Food for the Earth with BioCycle magazine, chronicles the 60% rise in the number of facilities processing municipal solid wastes from homes and businesses.
"We believe the primary driver for the increase in food composting is the improved climate for recovering and processing these materials," says the Composting Council's Simson. "Greater economics coupled with superior environmental impact should continue to spur development in this area of organics recovery and composting."--Steve Courtney, freelance science writer.
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