December 19, 2011 | General

Assessing Residential Collection Of Source Separated Organics

BioCycle December 2011, Vol. 52, No. 12, p. 25
New model from State of Georgia guides solid waste officials through a series of decisions related to implementing a residential SSO program. A tool kit is also available for communities moving forward with a program.
Abby Goldsmith and Joe Dunlop

The State of Georgia has strategically invested in diversion tools and facilities based on the outcome of a statewide waste characterization study conducted in 2005 by Science Applications International Corporation (SAIC). First the state reestablished its reduction goals for the most prevalent recyclables and invested in single-stream recycling hubs to facilitate collection and processing of paper, glass, plastic and metal. Next in line is the organics fraction. According to the statewide characterization study, an estimated 1.7 million tons of organics, including food scraps, yard trimmings and nonrecyclable paper, are being disposed in Georgia landfills each year (Figure 1).
Funded by a grant from Region 4 of the U.S. Environmental Protection Agency, the Georgia Department of Community Affairs and the Georgia Recycling Coalition commissioned SAIC to develop tools to assist local governments and other users with evaluating the feasibility of a residential source separated organics (SSO) collection program in their community. First the project team developed a model that would walk local governments and other users through decisions related to collecting organics from residents and estimating the operational, diversion, financial and greenhouse gas (GHG) impacts resulting from implementing a residential SSO collection program. Next, the project team provided tools to assist local governments that elect to move forward with implementing a residential SSO collection program.
In late 2011, the State of Georgia released the Source Separated Organics Collection Performance Model (the Model) and the Residential Source Separated Organics Collection Tool Kit (Tool Kit).

The SSO Collection Performance Model is developed in a Microsoft Excel® format. The model guides the user through a series of screens to provide information about current solid waste management practices and about the design of a potential residential SSO collection program, including impacts on other programs such as refuse and yard trimmings. The model requests key information from the user, including:
• Number of households to have access to the SSO collection program;
• Frequency of collection and the type of collection vehicles to be used;
• Types of organic materials to be collected;
• Amount and composition of MSW disposed;
• Projected participation and capture rate;
• Collection entity (municipal or private) and households served per route;
• Distance to and tipping fee at processing facility; and
• Likely revenues from sale of product.
The model provides access to default values for most of these fields based on actual data available. Users with more site-specific information can enter their own data specific to their planned program. For example, the model asks for an estimate of tons of organic materials to be collected. The default tonnage for these materials applies the Georgia statewide results from the 2005 composition study to the total tonnage disposed in that community. However, users can override the default values and insert their own composition data if available. Offering the option of accepting default assumptions in the model or entering site-specific input results in a tool that is valuable for both the user with limited knowledge of how a SSO collection program may operate in their community and for the most sophisticated user.
The output of the model provides information regarding the proposed residential SSO program, including: Estimated tonnage available; Projected tonnage of each material collected; Estimated cost; Estimated revenues/savings; Estimated cost per household; and Net impact on greenhouse gas emissions. In addition to using the SSO Collection Performance Model to estimate the impact of a particular program, it can be used to compare the performance of multiple residential SSO collection program designs and thus help communities decide which one best achieves their goals and objectives.
As part of the model development, SAIC worked with three communities across the state of Georgia to use the tool to determine the diversion, financial and other impacts of a “hypothetical” SSO collection program. The three test case examples include the following programs:
Example #1: Weekly curbside SSO collection program for all of the 10,000 households in the community. Accepts fruits, vegetables and bakery; yard trimmings (that are currently collected separately), and nonrecyclable paper. Municipality receives some revenue from sale of compost.
Example #2: Weekly curbside SSO collection program for 5,500 households. Accepts all food scraps and nonrecyclable paper. Yard trimmings are and will continue to be collected separately. Processor retains revenues from sale of product.
Example #3: A drop-off program for all food scraps, yard trimmings, and other organics (excluding wood) at a network of 19 existing centers in a County with a population of 16,000.
Table 1 shows calculations for Current Practices. Table 2 contains the assumptions. Table 3 provides results for each of these residential SSO collection programs. The tables are based on responses from communities and changed slightly for purposes of the article. The model does take into account the reduction in refuse tonnage, fuel, vehicles and personnel due to implementation of a SSO program. For example, it calculates the estimated number of refuse loads to be eliminated by implementation of an SSO program allowing the user to calculate the reduction in fuel costs. In addition, the model requests the user to identify the net impact in equipment and personnel based on existing refuse equipment and personnel being transitioned and utilized in the SSO program.
Accompanying the Model, the Tool Kit assists local governments with implementing a residential SSO program. For example, the Tool Kit contains a detailed 18-month implementation strategy. Included are a schedule, responsible party and stakeholders for each action item, and estimated cost. The action items are divided into four phases: program planning, pilot program (should the community choose to start with a pilot), community-wide implementation and post-implementation.
The Tool Kit also contains examples of materials that can be used to gather input and information about the program. A sample prepilot survey of residents is designed to determine how much food waste may be generated by households in the pilot area, the likelihood that residents will participate in a SSO collection program, and for those that are likely to participate, the type of organic material they would separate for collection. The survey also elicits concerns about organics separation and potential ways to address them. A sample post-pilot survey is included to determine why residents chose to participate or not to participate, their degree of satisfaction with the program, and what could be improved before the SSO program is expanded.
Next, the Tool Kit includes sample public education and information materials that could be printed and distributed or posted online, including a fact sheet and letters to residents introducing both pilot and community-wide programs. The Tool Kit also includes reporting documents for haulers of organics, recyclables and solid waste; descriptions, examples of and links to information regarding containers and vehicles; links to information regarding organics processing facilities in EPA Region 4; and more detailed waste composition data than that provided in the model alone.
For more information on the Source Separated Organics Collection Performance Model or the Residential Source Separated Organics Collection Tool Kit, contact the Georgia Department of Community Affairs at or the Georgia Recycling Coalition at
Abby Goldsmith is an Assistant Vice President at SAIC focusing on solid waste services. Joe Dunlop is the Program Coordinator with the Georgia Department of Community Affairs.

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