learning from nature
Composting provides us with the best natural example of zero waste in action. Plants grow, flower, and fruit, and then wither and decompose, returning valuable resources to the soil in the process. Building zero waste programs requires us to restructure our systems and our habits to attempt to match the simple elegance of that natural model. Creating closed loop systems is not impossible, but it requires that we re-evaluate the linear models of resource use we have relied on since becoming an industrial society.
Composting is more than an isolated solid waste management technique. We are organic beings, and the vast majority of our discards are organic as well. Recovering and composting this portion of our waste stream is key to improving our ability to reduce landfilled waste. The Zero Emissions Research Institute (ZERI) specializes in the development of sustainable systems with the goal of recovering and adding value to the "by-products" produced by our resource use practices. This total system approach, so closely linked to nature's design, is zero waste.
Beer bakes bread and feeds fishBreweries in Namibia, Sweden, Canada, and Japan are converting the waste protein and fiber from the
brewing process into valuable products, generating additional income and jobs. For more information, see the ZERI website.
Composting is the controlled biological decomposition of organic matter, such as food and yard wastes, into humus, a soil-like material. Composting is nature's way of recycling organic waste into new soil, which can be used in vegetable and flower gardens, landscaping, and many other applications. Composting is the controlled decomposition of organic materials, such as leaves, grass, and food scraps, by microorganisms. The result of this decomposition process is compost, a crumbly, earthy- smelling, soil-like material. Yard trimmings and food scraps make up about 25 percent of the waste U.S. households generate, so composting can greatly reduce the amount of waste that ends up in landfills or incinerators.
Municipal Solid Waste - Composting: from the U.S. EPA website.
Backyard composting. Hundreds of thousands of individuals across the country compost in their own backyards, typically in a fenced off area or bin. Backyard composting provides a convenient way to reduce the volume of trash a household produces. It also provides a valuable product that can enhance the soil and increase the growth and health of the yard.
Yard trimmings composting. Composting also occurs on a large scale, operated by private sector firms or community public works departments. At these sites, the compostable material is taken to a central location. There, it is typically processed in aerated windrows, where organics are formed into rows or long piles. Some sites will add compostable municipal solid waste (MSW) into the mix to keep items out of the landfill. The finished compost can be sold, given away, or used by the company or municipality in local landscaping projects.
Mixed MSW composting. Composting of mixed MSW is another option. This generally occurs at a medium-to-large scale facility, operated by private sector firms or community public works departments. Generally, mixed MSW is received at the site. Recyclables such as glass and aluminum, and non-compostables are removed early in the process. The remaining organic material is composted, generally using aerated windrows. In-vessel composting, where the material is left to decompose while enclosed in a temperature and moisture controlled chamber, is another possibility. Final screening steps remove any remaining plastic film and similar contents. The finished compost can be sold, given away, or used by the company or municipality in local landscaping projects.
Vermicomposting. Although not significant in terms of waste diversion, vermicomposting is being used in some places and is popular in classrooms as a teaching tool. This method of composting uses a container of food scraps and a special kind of earthworm known as a red wiggler. Over time, the food is replaced with worm droppings, a rich brown matter that serves as an excellent natural plant food. Vermicomposting requires less space than normal composting methods, and is, therefore, ideal for classrooms, apartments, and other settings in high-density urban areas.
Other innovative uses. Visit EPA's Composting Page to learn about other uses of MSW compost-from erosion control to bioremediation.
From EPA’s Composting website.
Examples of model composting programs
Don’t Throw Away That Food: Strategies for Record-Setting Waste Reduction
by Brenda Platt and Joanne Goodwin, 1998, fact sheet packet (24 pages). - View Online at: www.ilsr.org/recycling. EPA-530-F-98-023: two-color printed copies available free through the RCRA hotline 1-800-424-9346 (within U.S.),1-703-412-9810 (outside U.S. and Washington, DC metro area).
Sample Case Studies: Don't Throw Away That Food - Waste Reduction Strategies: ILSR's food waste reduction website.
From the Indiana Department of Environmental Management: www.in.gov.
As Indiana communities plan for the future, yard waste management programs are being recommended as a way to achieve solid waste diversion goals and comply with the Yard Waste Ban which went into effect on September 30,1994.
The yard waste streams show varying characteristics. Leaves ranged from 20% to 50%, grass clippings accounted for 5% to 64%, and brush ranged from 19% to 45% of the yard waste stream. The wide variation in the characteristics of the residential yard waste stream emphasizes the need for communities to study the composition of their own yard waste characteristics before planning any programs to manage this portion of the waste stream.
Organics Recycling Showcase
From the Iowa Department of Natural Resources: Iowa DNR: Organics and Composting website.
About 46 percent of the waste landfilled in Iowa is organic. Organics include wood, food, paper and yard wastes.
By diverting organic material from the landfill, Iowa can add value to its agricultural products and expand markets for recycled goods. One of the best opportunities for organics diversion is composting. Here are several programs and resources to learn more about composting and organics recycling in Iowa.
Iowa DNR: Mulch Iowa website.
Native forest soil has a rich, thick, nutrient-packed layer of natural organic material that aids plant growth by protecting delicate roots from temperature extremes, pests, and water evaporation.
Although soil in an urban environment often lacks this vital layer, Iowans can recreate it using mulch.
Excerpts from the Trash Cutters’ Award Winners of the California Integrated Waste Management Board:
City of Palo Alto: 1998 Organics Management Trash Cutters Award
The largest organics management program in the City of Palo Alto is the composting facility, which opened in March 1977. Today this facility processes 17,000 tons of yard trimmings each year. The yard trimmings are received from city crews, franchise refuse collectors, gardeners, tree contractors, and residents.
With organic waste making up approximately 30 percent of the waste stream, the City of Palo Alto established a composting facility in 1997 that processes 17,000 tons of yard trimmings each year. The city in turn produces compost that is sold in bulk and bags. The bulk sale operation, which began in 1993, has sold nearly 60,000 cubic yards of compost, generating more than $252,000 for the City. The city also offers free backyard composting workshops taught by certified composters. In addition, compost give-a-way events are held five times a year to educate residents about composting, and the benefits of participating in the yard waste curbside collection program.
Demand for the product has grown steadily. In order to meet this growing demand, they are mixing horse stable bedding into the finished product to increase volume, which recycles a new waste stream within the city as well as enhancing revenue.
The city's school outreach and education programs sponsor a variety of programs and resources for teachers, designed to support environmental educational curricula for elementary-age classes. As a part of this program, composting is discussed through videos, interactive computer programs, curriculum guides, reading materials, tours and presentation from the city's Wizard program.
Working in conjunction with Santa Clara County, Palo Alto started offering residents backyard composting workshops at no charge. Annually there are approximately 24 workshops with 450 participants from the City of Palo Alto. The workshops are taught by Certified Master Composters who are volunteers from the community. In exchange for their training, these volunteers contribute a minimum of 50 hours of volunteer time to the community, teaching the public about composting via workshops and information booths at special events.
At the end of the 1.5 hour workshop, residents receive a voucher for a reduced-cost compost bin; the Biostack Composter ($27.00), or the Seattle Composter ($15.00). Residents purchase their bins at the Palo Alto Landfill where the compost bins are stored. Approximately 600 compost bins have been sold.
San Francisco Department of the Environment: 2001 Best Organics Management Program Trash Cutters Award
San Francisco’s organic materials, which include food residuals, food soiled paper, wax corrugated cardboard, yard trimmings, and wood are managed and diverted from the landfill through a variety of programs. The city has developed partnerships with many different nonprofit entities, Norcal garbage and recycling companies, dairy farmers, and local schools and colleges. The San Francisco Recycling Program provided help with program planning and development, funding for equipment, outreach, and technical assistance for program implementation.
The city’s comprehensive organics diversion program includes: (1) edible discarded produce and other food redistributed by the San Francisco Food Bank and prepared foods from restaurants redistributed by Food Runners; (2) food processing waste (for example, brewery grains, tofu residuals) and inedible produce used by dairy farmers for cattle feed; (3) bakery discards used to produce dry animal feed products; (4) food service grease and meat collection for rendering; (5) home, school, and university cafeteria on-site food scrap and yard trimming composting; (6) on-site city Recreation and Parks Department landscape debris for mulching and manure composting; (7) clean wood used for composting or as biomass boiler fuel; and (8) source separated pre- and postconsumer food scraps, food soiled paper, waxed corrugated boxes, and plant/floral trimmings from schools, households, and a wide variety of commercial generators citywide composted into marketed products, some of which return to the city.
The Food Bank edible produce redistribution program was developed and initially funded in 1996 by a San Francisco Recycling Program (SFRP) grant that provided a dedicated truck and driver to collect daily from the San Francisco produce terminal companies. The SFRP provided follow-up grants over the next several years to help expand edible food recovery.
The commercial composting collection program was developed and piloted starting at the produce terminal later in 1996 through a working partnership between the city and Sunset Scavenger Company (SSC), the city’s permitted hauler. Since 1996 SFRP has contracted with a team to help provide on-site training, monitoring, and follow-up for businesses to assist participation. SFRP worked with SSC to develop an incentive rate structure, which provides a 25 percent discounted rate (from regular garbage rates) for compostables collected in the program. These actions have been instrumental in the success and expansion of the commercial composting program.
Over the last 12 years, the SFRP has worked closely with the San Francisco League of Urban Gardeners as a contractor to develop and implement programs for home composting education (including free workshops, demonstration centers, and “rotline”), discount composting bin distribution, volunteer composting and gardening educator training program, and school composting programs.
The innovative program of residential food collection is part of the citywide 3 color-coded wheeled cart system. The “Fantastic 3” program combines the collection of residential single and multifamily households with small businesses. Participants are provided with three carts: for residents a 32-gallon green cart for compostables collection along with a 2-gallon kitchen pail for sorting food scraps; a 32-gallon blue cart for commingled recycling of all bottles, cans, and paper; and a 32-gallon black cart for trash that is not compostable or recyclable. The SFRP helped develop and fund outreach, methods, and materials. Program staff obtain contract assistance in collecting and evaluating program data, including surveying targeted households. Surveys have revealed high resident satisfaction, with 90 percent preferring the new 3-cart program to their old program.
Composting Facts and Figures