METHODOLOGY FOR ESTIMATING MUNICIPAL SOLID WASTE RECYCLING BENEFITS NOVEMBER 2007 ------- TABLE OF CONTENTS PURPOSE 3 THE LINK BETWEEN WASTE MANAGEMENT, CLIMATE CHANGE, AND ENERGY 3 The MSW Characterization Report 4 The Waste Reduction Model 4 METHODOLOGY FOR DERIVING BENEFITS 4 Materials Crosswalk 6 Organics 6 Paper and Paperboard Products 6 Glass Products 7 Metal Products 7 Plastics in Products 7 Other Products 8 WARM Walk-Through 8 Baseline Scenario 8 Alternate Scenario 9 WARM Benefit Results 10 2 ------- PURPOSE This "Methodology for Estimating Municipal Solid Waste (MSW) Recycling Benefits" is intended to provide a clear and complete explanation of the process used by EPA to develop estimates of the benefits associated with municipal solid waste (MSW) recycling. This methodology helps to serve as a crosswalk and explains how EPA's MSW characterization data (as reported in "Municipal Solid Waste Generation, Recycling, and Disposal in the United States: Facts and Figures for 2006" (Characterization Report))1, are input into the Waste Reduction Model (WARM)2 in order to derive benefit estimates. Also, this methodology provides further specifics regarding the Characterization Report and WARM, and helps to further document the linkages that exist between waste management, and its potential contributions to climate change and energy conservation. THE LINK BETWEEN WASTE MANAGEMENT, CLIMATE CHANGE, AND ENERGY The disposal of solid waste produces greenhouse gas emissions in a number of ways. First, the anaerobic decomposition of waste in landfills produces methane, a greenhouse gas 21 times more potent than carbon dioxide. Second, the incineration of waste also produces carbon dioxide as a by-product. Additionally, in transportating waste for disposal, greenhouse gases are emitted due to the combustion of fossil fuels. Finally, fossil fuels are also required for extracting and processing the raw materials necessary to replace those materials that are being disposed with new products. Waste prevention and recycling—jointly referred to as waste reduction—help us better manage the solid waste we generate. But preventing waste and recycling also are potent strategies for reducing greenhouse gas emissions and conserving energy. Together, waste prevention and recycling: • Reduces methane emissions from landfills. Waste prevention and recycling (including composting) divert organic wastes from landfills, thereby reducing the methane released when these materials decompose. • Reduces emissions from incinerators. Recycling and waste prevention allow some materials to be diverted from incinerators and thus reduce greenhouse gas emissions from the combustion of waste. • Reduces emissions from energy consumption. Recycling saves energy - because manufacturing goods from recycled materials typically requires less energy than producing goods from virgin materials. Waste prevention is even more effective at saving energy - because when people reuse things or when products are made with less material and/or greater durability, less energy is usually needed to extract, transport, and process raw materials and to manufacture replacement products. What's more, when energy demand decreases, fewer fossil fuels are burned and less carbon dioxide is emitted to the atmosphere. • Increases storage of carbon in trees. Trees help absorb carbon dioxide from the atmosphere and store it in wood, in a process called carbon sequestration. Waste prevention and recycling of paper products allow more trees to remain unharvested, where they can continue to remove carbon dioxide from the atmosphere. 1 The Municipal Solid Waste Generation, Recycling, and Disposal in the United States: Facts and Figures for 2006 can be found on-line at http://www.epa.gov/epaoswer/non-hw/muncpl/msw99.htm 2 The WARM Model can be found on-line at http://epa.gov/climatechange/wvcd/waste/SWMGHGreport.html. 3 ------- DESCRIPTION OF DATA AND MODEL USED The following two key information sources were used by EPA; first, as a basis for identifying the quantities of MSW being recycled, and secondly, for assessing the benefits that could be ascribed to these recycling achievements. The MSW Characterization Report The Environmental Protection Agency has collected and reported data on the generation and disposal of waste in the United States for more than 30 years. We use the information to measure the success of municipal solid waste (MSW) reduction and recycling programs across the country. The Waste Reduction Model WARM is an Environmental Protection Agency (EPA) model that covers 34 types of materials and five waste management options: source reduction, recycling, combustion, composting, and landfilling. WARM accounts for upstream energy and carbon emissions, transportation distances to disposal and recycling facilities, carbon sequestration, and utility offsets that result from landfill gas collection and combustion. WARM assesses four main stages of product life-cycles, all of which provide opportunities for GHG and energy emissions and/or offsets. These stages are: raw material acquisition, manufacturing, recycling, and waste management. In 2006, the U.S. recycled 32.5 percent (or 81.8 million tons) of its waste, up from 31.9 percent in 2005. This resulted in 49.7 million metric tons of carbon equivalent (MTCE) saved, or the emissions equivalent of taking 39.4 million cars off the road for one year. In addition, 1.3 quadrillion BTUs of energy were saved, which is enough energy to power 13 percent of U.S. residences for one year. METHODOLOGY FOR DERIVING BENEFITS The benefits of MSW recycling were calculated using WARM. As noted above, generating these benefit estimates requires inputting data on MSW recycling into WARM. However for some materials, the Characterization Report and WARM do not have identical categories. More specifically, WARM contains fewer material categories than are listed in the Characterization Report. While some categories are highly similar and correct placement of the data into WARM is readily apparent, for modeling purposes it was necessary to establish standard assumptions to facilitate this process for certain specific materials. The following section explains the methodology and assumptions used by EPA to determine the GHG and energy benefits of the U.S. national 32.5 percent recycling rate based on 2006 data. Inputting data into WARM and running the model involves two major steps as summarized here. Step one involves using the Characterization Report to identify the materials to be used as inputs to WARM. The Characterization Report Data Tables3 list the MSW materials that can be input into WARM. Table 1 below provides a general crosswalk of the material categories in the MSW Characterization Report, as compared to the categories that are available within the WARM model. A more detailed discussion of this process for specific materials has been organized 3 The 2006 MSW Characterization Data Tables are located at http://www.epa.gov/epaoswer/non- hw/muncpl/ms w9 9. htm 4 ------- below in the following section, grouped according to their respective material category and associated table numbers from the MSW Characterization Report. Step two involves using WARM to distinguish between a baseline and alternate scenario. This requires decisions such as determining the amount landfilled or combusted in the baseline scenario and recycled or source reduced in the alternate scenario. The methodology EPA used to determine national recycling benefits is discussed in the WARM walk-through section below. Table 1. Crosswalk between Material Categories in the MSW Characterization Report and WARM MSW Characterization Report WARM Table4 Material Category Material Category Table 2 Textiles Carpet Table 2 Wood Dimensional Lumber Table 2 Food Scraps Food Scraps Table 2 Yard Trimmings Yard Trimmings Table 4 Total Newspapers Newspaper Table 4 Books Textbooks Table 4 Magazines Magazines/third-class mail Table 4 Office-type papers Office paper Table 4 Telephone Directories Phonebooks Table 4 Standard Mail Magazines/third-class mail Table 4 Other Commercial Printing Mixed Paper, office Table 4 Corrugated Boxes Corrugated Cardboard Table 4 Folding Cartons Mixed Paper, residential Table 4 Bags and Sacks Mixed Paper, residential Table 5 Total Glass Glass Table 6 Ferrous Metals Steel Cans Table 6 Lead Mixed Metals Table 6 Total Steel Packaging Steel Cans Table 6 Total Aluminum Packaging Aluminum Cans Table 7 PET PET Table 7 HDPE HDPE Table 7 LDPE/LLDPE LDPE Table 7 PP Mixed Plastics Table 7 PS Mixed Plastics Table 7 Other resins Mixed Plastics Table 8 Rubber in Tires Tires 4 The tables can be found on-line in the MSW Characterization Report Data Tables at http://www.epa.gov/epaoswer/non-hw/muncpl/msw99.htm 5 ------- Materials Crosswalk Organics Table 2 of the Characterization Report Data Tables provides details regarding the recovery of food scraps and yard trimmings. Both categories are represented in the tables and WARM under the same name. Table 2. Organics Crosswalk WARM Material Characterization Report Material Generated (000 tons) Recovered (000 tons) Food Scraps Food Scraps 31,250 680 Yard Trimmings Yard Trimmings 32,400 20,100 Paper and Paperboard Products Table 4 of the Characterization Report Data Tables provides details regarding the paper and paperboard categories. The category "total newspaper" is listed as a combination of "newsprint" and "groundwood inserts". To calculate the benefits of these materials, they are all classified as "newspaper". WARM's category "textbooks" is used to measure the benefits of the material the Characterization Report refers to as "books". "Telephone directories" in the Characterization Report and "phonebooks" in WARM are assumed to be the same items. Similarly, "corrugated boxes" in the Characterization Report and "corrugated cardboard" in WARM are assumed to refer to exactly the same material. The category "mixed paper, office" is used as a proxy in WARM for the "other commercial printing" category. "Standard mail" and "magazines" from Table 4 of the Characterization Report are grouped together for measurement in WARM's "magazines/third-class mail" category, while "folding cartons" and "bags and sacks" are added together in WARM's "mixed paper, residential" category. Table 3. Paper and Paperboard Crosswalk WARM Material Characterization Report Material Generated (000 tons) Recovered (000 tons) Corrugated Cardboard Corrugated Boxes 31,430 22,630 Magazines/Third-class mail Magazines and Standard Mail 8,460 3,320 Newspaper Total Newspaper 12,360 10,870 Office Paper Office-type Papers 6,320 4,150 Phonebooks Telephone Directories 680 130 Textbooks Books 1,130 290 Mixed paper (residential) Folding Cartons and Bags and Sacks 6,910 1,230 Mixed paper (offices) Other Commercial Printing 6,630 1,400 6 ------- Glass Products Table 5 of the Characterization Report Data Tables provides details regarding the glass category. The category "total glass" is listed as a combination of glass in durable goods and glass containers and packaging. This total amount from Table 5 is used in WARM's "glass" category to calculate benefits. Table 4. Glass Crosswalk WARM Material Characterization Report Material Generated (000 tons) Recovered (000 tons) Glass Total Glass 13,200 2,880 Metal Products Table 6 of the Characterization Report Data Tables provides details regarding the metals category. "Ferrous metals" are classified in the WARM category "steel cans" based on Exhibit 8- 1 of "Solid Waste Management and Greenhouse Gases: A Life-Cycle Assessment of Emissions and Sinks." Lead does not have a matching category in WARM, and is thus classified as "mixed metals." "Total steel packaging" is categorized as "steel cans" and "total aluminum packaging" is classified as "aluminum cans" in the WARM. Table 5. Metal Crosswalk WARM Material Characterization Report Material Generated (000 tons) Recovered (000 tons) Aluminum Cans Total Aluminum Packaging 1,940 690 Steel cans Total Steel Packaging and Ferrous Metals 14,220 5,080 Mixed Metals Lead 1,190 1,180 Plastics in Products Table 7 in the Characterization Report Data Tables provides detail regarding the plastics category. The "PET," "HDPE," and "LDPE/LLDPE" categories all have matching categories in WARM, and thus are classified appropriately. The "Solid Waste Management and Greenhouse Gases: A Life-Cycle Assessment of Emissions and Sinks" states in Exhibit 8-1 that the emissions and energy use related to plastics such as "PP" (polypropylene), "PS" (polystyrene) and "other resins" should be measured using "mixed plastics" in WARM. 7 ------- Table 6. Plastics Crosswalk WARM Material Characterization Report Material Generated (000 tons) Recovered (000 tons) PET PET 6,040 580 HDPE HDPE 6,560 280 LDPE LDPE/LLDPE 3,060 620 Mixed Plastics Other Resins, PP, PS 12,160 560 Other Products Table 2 in the Characterization Report Data Tables provides detail regarding the categories of both wood and textiles. The Solid Waste Management and Greenhouse Gases: A Life-Cycle Assessment of Emissions and Sinks", states in Exhibit 8-1 that "wood" should be measured as "dimensional lumber' in WARM, and that "textiles" should be classified as "carpet." "Rubber in tires", which can be found in Table 8 of the Data Tables, is classified as "tires" in WARM. Table 7. Other Materials Crosswalk WARM Material Characterization Report Material Generated (000 tons) Recovered (000 tons) Carpet Textiles 11,840 1,810 Dimensional Lumber Wood 13,930 1,310 Tires Rubber in Tires 2,490 870 WARM Walk-Through WARM differentiates between two different scenarios: baseline and alternate. Normally, the baseline scenario refers to the current or 'business as normal' situation and the alternate scenario depicts the change in waste management that is to be modeled to quantify benefits. WARM also allows the user to change certain criteria, such as distances to different management facilities or information on landfill gas recovery. EPA uses the national averages to develop its national benefits estimates. Please note if these criteria are changed, the numbers may not correspond to EPA's numbers. 8 ------- Baseline Scenario For the purposes of this exercise, EPA assumed that 87.5 percent of the recovered material was landfilled and 12.5 percent was combusted with energy recovery for the baseline scenario5. EPA only modeled the amount of material recycled (not generated), as stated by the Characterization Report, since the benefits numbers generated relate specifically to the benefits of recycling the material. Table 8 presents the actual numbers EPA plugged into WARM for the baseline. Table 8. Snapshot of Baseline Scenario Tons Baseline Source Tons Tons Tons Tons Material Generation Reduced Recycled Landfilled Combusted Composted Aluminum Cans 690,000 604,000 86,000 NA Steel Cans 5,080,000 4,445,000 635,000 NA Copper Wire NA Glass 2,880,000 2,520,000 360,000 NA HDPE 580,000 507,500 72,500 NA LDPE 280,000 245,000 35,000 NA PET 620,000 542,500 77,500 NA Corrugated Cardboard 22,630,000 19,801,000 2,829,000 NA Magazines/Third-class Mail 3,320,000 2,905,000 415,000 NA Newspaper 10,870,000 9,511,000 1,359,000 NA Office Paper 4,150,000 3,631,000 519,000 NA Phonebooks 130,000 114,000 16,000 NA Textbooks 290,000 254,000 36,000 NA Dimensional Lumber 1,310,000 1,146,000 164,000 NA Medium-density Fiberboard NA Food Scraps 680,000 NA NA 595,000 85,000 Yard Trimmings 20,100,000 NA NA 17,587,500 2,512,500 Grass NA NA Leaves NA NA Branches NA NA Mixed Paper (general) NA NA Mixed Paper (primarily residential) 1,230,000 NA 1,076,000 154,000 NA Mixed Paper (primarily from offices) 1,400,000 NA 1,225,000 175,000 NA Mixed Metals 1,180,000 NA 1,032,500 147,500 NA Mixed Plastics 560,000 NA 490,000 70,000 NA Mixed Recyclables NA NA Mixed Organics NA NA Mixed MSW NA NA NA Carpet 1,810,000 1,584,000 226,000 NA Personal Computers NA Clay Bricks Alternate Scenario NA NA Concrete NA NA Fly Ash NA NA Tires 870,000 761,000 109,000 NA 5 2006 MSW Characterization Report Data Tables, Table 29. 9 ------- The alternate scenario assumes that all materials from the baseline are recycled. Table 9 provides a snapshot of this alternative assessment, as modeled by WARM. Table 9. Snapshot of Alternative Scenario Tons Tons Tons Tons Tons Material Generated Recycled Landfilled Combusted Composted Aluminum Cans 690,000 690,000 NA Steel Cans 5,080,000 5,080,000 NA Copper Wire NA Glass 2,880,000 2,880,000 NA HDPE 580,000 580,000 NA LDPE 280,000 280,000 NA PET 620,000 620,000 NA Corrugated Cardboard 22,630,000 22,630,000 NA Magazines/Third-class Mail 3,320,000 3,320,000 NA Newspaper 10,870,000 10,870,000 NA Office Paper 4,150,000 4,150,000 NA Phonebooks 130,000 130,000 NA Textbooks 290,000 290,000 NA Dimensional Lumber 1,310,000 1,310,000 NA Medium-density Fiberboard NA Food Scraps 680,000 NA 680,000 Yard Trimmings 20,100,000 NA 20,100,000 Grass NA Leaves NA Branches NA Mixed Paper (general) NA Mixed Paper (primarily residential) 1,230,000 1,230,000 NA Mixed Paper (primarily from offices) 1,400,000 1,400,000 NA Mixed Metals 1,180,000 1,180,000 NA Mixed Plastics 560,000 560,000 NA Mixed Recyclables NA Mixed Organics NA Mixed MSW NA NA Carpet 1,810,000 1,810,000 NA Personal Computers NA Clay Bricks NA NA NA Concrete NA NA Fly Ash NA NA Tires 870,000 870,000 NA 10 ------- WARM Benefit Results WARM generates benefits numbers once the baseline and alternate scenarios are complete. These benefits estimates are generated in either metric tons of carbon equivalent (MTCE), metric tons of carbon dioxide equivalent (MTC02E), or British thermal units (BTU). In addition, WARM calculates other conversions, such as the number of cars of the road or the number of households' annual energy consumption. Further conversions of these units can be estimated using the Greenhouse Gas Equivalencies Calculators at http://www .usctcgateway. gov/tool/. Using WARM as described above, EPA has estimated the total GHG Emission Reductions and Energy Savings associated with the national MSW recycling rate of 32.5% (or 82 million tons) achieved by the U.S. in 2006, as provided below in Table 10. Table 10. WARM Benefit Results Benefits Conversions 49.7 million MTCE 39.4 million cars off the road 182.2 million MTC02E 39.4 million cars off the road 1,288 trillion BTU 6.8 million households annual energy consumption 222.1 million barrels of oil 10.3 billion gallons of gas 11 ------- |