Compost Quality Program

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California Integrated Waste Management Board

CIWMB Helps Increase Number of Registered Compost Producers

Because organic materials, including landscape and tree trimmings, grass clippings, and food scraps, comprise 30 percent of California’s waste stream, the California Integrated Waste Management Board (CIWMB) designated organic materials management as one of its strategic planning priority areas. An internal "Greening Team Performance Plan" for this priority material calls for focused collaboration with partners in state and local government, the landscape industry, recycling and manufacturing sectors, and other end-use sectors. The plan sets a goal of diverting an additional 5-7 million tons of organic materials from landfills by the year 2000. This includes diverting an additional 1.5-2 million tons of landscape and tree trimmings from landfills. Diversion of, and use of compost and mulch made from organic materials reduces environmental impacts at landfills, including reduced green house gas emissions, and yields benefits such as soil revitalization, erosion control, and water conservation.

In addition to the above, the plan also calls for increasing the number of compost producers registered. The bar chart shown in this link depicts the cumulative total of compost facilities registered, and the number of facilities that are in the application process. The CIWMB has actively promoted the voluntary dissemination of verifiable information about compost product characteristics since 1993 and funded initial work to develop a laboratory practices manual and a verification procedures manual.

Based on this work, a registration program was developed focused on ensuring that registered producers comply with applicable CIWMB regulations, disclose feedstock materials, follow specified quality assurance and quality control protocols, provide samples for independent lab analysis of specified parameters, and disclose results of those lab analyses. This helps ensure that end users can evaluate the physical and chemical characteristics of compost and, as a result, make more informed buying decisions. Physical and chemical properties currently tested include bulk density, particle size, pH, salinity, and organic matter content. Compost producers who meet the disclosure criteria can display the registration seal on their product. With registration, end users, landscapers, horticulturists, nurserymen, groundskeepers, farmers, and others in green industries can have extra confidence about the characteristics and consistency of the compost products they use.

To further promote markets for compost, in 1999, the Board approved a contract to expand its compost product quality disclosure program. In this contract the Board will work to build partnerships with compost industry organizations to enhance the existing statewide compost product quality disclosure program. Specifically, the contract calls for development, with input from the United States Composting Council, the Organic Materials Review Institute, and other interested parties, new and revised compost product quality disclosure parameters, and revised testing and verification protocols that are applicable in a California-specific context. Additional disclosure parameters to be evaluated will include cation exchange capacity, humic acid content, organic carbon content, inorganic nitrogen, ammonium nitrate, total nitrogen, salinity, maturity and other factors. The new and revised disclosure parameters, and updated lab practices and inspection verification manuals will serve as the basis for expanding the registration program.

The contract would also require promotion of the use and application of these updated parameters to help create new and expanded markets for compost in California. Market outreach and educational efforts will target both compost producers to increase the number of registered facilities and end-users to increase market demand for compost, including for use in landscaping.

Specific market outreach deliverables under this proposed contract include:

Two workshops targeting compost facility inspectors.

Four workshops targeting compost end users.

New compost product quality brochures.

Promoting the compost product quality disclosure program at five or more conferences in California.

Staff is now in the process of completing the first phase of that contract. To date, the most important outcome from this contract, developed with input from key industry experts, is a compost maturity index. This index will help ensure that compost producers are disclosing maturity measurements about their product. This will allow customers to better assess the maturity and stability of the compost they purchase. The index will also allow end-users to better evaluate the compost product for the end-use they have in mind.

In addition to the above, staff is also beginning work on the second part of the contract, which calls for the development of education and outreach materials. These materials will be promoted at workshops and conferences to increase both the number of registered facilities and the market demand for compost products. Four end-user workshops are planned and will be announced this spring. Workshops are tentatively planned for San Diego, Los Angeles, San Jose and Alameda. Staff is currently in discussion with potential local government cosponsors to host these workshops. It is anticipated that the workshops will take place in August 2000.