high-density polvethylene(HDPE/2). used for milk and water containers and detergent bottles. In 1987, more than 150 million pounds of plastic soft drink bottles were recycled. Even so, less than five percent of the available scrap plastic is being recycled. It is anticipated that all of the other types of lastics will be recycled in greater quantities in the future, however, as processing technologies found in MSw.Glass to be reprocessed is often separated by color into categories of clem es of pas o? Glass is also a commonly recycled material. Container glass(for food and beverage packing), flat amber Ferrous Metals (Iron and steel) The largest amount of recycled steel has traditionally come from large items such as cars and appliances. Many communities have large scrap metal piles at the local landfill or transfer station. In many cases, the piles are unorganized and different metals are mixed together, making them unattractive to scrap metal buyers. Steel can recycling is also becoming more popular. Steel cans, used as juice, soft drink, and food containers, are easily separated from mixed recyclables or municipal solid waste using large magnets(which also separate other ferrous metals Nonferrous Metals. Recyclable nonferrous metals are recovered from common household items (outdoor furniture, kitchen cookware and appliances, ladders, tools, hardware); from construction and recycled if they are sorted and free of foreign materials such as plastics, fabrics, and rubber als as ucg demolition projects(copper wire, pipe and plumbing supplies, light fixtures, aluminum siding, gutter and downspouts, doors, windows); and from large consumer, commercial, and industrial pro (appliances, automobiles, boats, trucks, aircraft machinery ) Virtually all nonferrous met Yard Wastes Collected Separately. In most communities yard wastes are collected separately. The composting of yard wastes has become of great interest as cities and towns seek to find ways in which to achieve mandated diversion goals. Leaves, grass clippings, bush clippings, and brush are the most commonly composted yard wastes Stumps and wood are also compostable, but only after they have been chipped to produce a smaller more uniform size. Composting of the organic fraction of MSwis also becoming more popular. Construction and Demolition Wastes. In many locations construction and demolition(C&D)wastes are now being processed to recover marketable items such as wood chips for use as a fuel in biomass combustion facilities, aggregate for concrete in construction projects, ferrous and nonferrous metal for remanufacture, and soil for use as fill material. The reprocessing of C&D wastes is gaining in popularity as disposal fees at landfills continue to increase. When disposal fees were below 5 dollars per ton(early 1970s), reprocessing was not economically feasible. Today(1992), with average landfill disposal fees approaching 60 dollars per ton in many parts of the country, the reprocessing of C&D wastes is economically feasible Specifications for Recovered Materials As the amount of material recovered from msw continues to increase as communities develo programs to meet waste diversion goals, materials specifications will become an important factor. In general, there is less contamination in source-separated material, but collection is more labor-intensive, and many communities are choosing to sort all materials at a central materials recovery facility (MRF) In many regions, markets for materials are not keeping pace with the volume collected, and it is expected that buyers will tighten specifications; as a result vendors will no longer have assured markets, and will be competing to sell materials. As the specifications for recovered materials become more restrictive, recovery program managers must consider buyer specifications carefully when choosing collection and sorting systems, especially where large capital expenditures are involved 13-6 Future Changes in Waste Composition In terms of solid waste management planning, knowledge of future trends in the composition of solid wastes is of great importance. For example, if a paper-recycling program were instituted on the basis of current distribution data and if paper production were subsequently eliminated, such a program would more than likely become a costly white elephant. Although this case is extreme, it nevertheless13-9 high-density polyethylene (HDPE/2), used for milk and water containers and detergent bottles. In 1987, more than 150 million pounds of plastic soft drink bottles were recycled. Even so, less than five percent of the available scrap plastic is being recycled. It is anticipated that all of the other types of plastics will be recycled in greater quantities in the future, however, as processing technologies improve. Glass. Glass is also a commonly recycled material. Container glass (for food and beverage packing), flat glass (e.g., window glass), and pressed or amber and green glass are the three principal types of glass found in MSW. Glass to be reprocessed is often separated by color into categories of clear, green, and amber. Ferrous Metals (Iron and Steel). The largest amount of recycled steel has traditionally come from large items such as cars and appliances. Many communities have large scrap metal piles at the local landfill or transfer station. In many cases, the piles are unorganized and different metals are mixed together, making them unattractive to scrap metal buyers. Steel can recycling is also becoming more popular. Steel cans, used as juice, soft drink, and food containers, are easily separated from mixed recyclables or municipal solid waste using large magnets (which also separate other ferrous metals). Nonferrous Metals. Recyclable nonferrous metals are recovered from common household items (outdoor furniture, kitchen cookware and appliances, ladders, tools, hardware); from construction and demolition projects (copper wire, pipe and plumbing supplies, light fixtures, aluminum siding, gutters and downspouts, doors, windows); and from large consumer, commercial, and industrial products (appliances, automobiles, boats, trucks, aircraft, machinery). Virtually all nonferrous metals can be recycled if they are sorted and free of foreign materials such as plastics, fabrics, and rubber. Yard Wastes Collected Separately. In most communities yard wastes are collected separately. The composting of yard wastes has become of great interest as cities and towns seek to find ways in which to achieve mandated diversion goals. Leaves, grass clippings, bush clippings, and brush are the most commonly composted yard wastes. Stumps and wood are also compostable, but only after they have been chipped to produce a smaller more uniform size. Composting of the organic fraction of MSW is also becoming more popular. Construction and Demolition Wastes. In many locations construction and demolition (C&D) wastes are now being processed to recover marketable items such as wood chips for use as a fuel in biomass combustion facilities, aggregate for concrete in construction projects, ferrous and nonferrous metals for remanufacture, and soil for use as fill material. The reprocessing of C&D wastes is gaining in popularity as disposal fees at landfills continue to increase. When disposal fees were below 5 dollars per ton (early 1970s), reprocessing was not economically feasible. Today (1992), with average landfill disposal fees approaching 60 dollars per ton in many parts of the country, the reprocessing of C&D wastes is economically feasible. Specifications for Recovered Materials As the amount of material recovered from MSW continues to increase as communities develop programs to meet waste diversion goals, materials specifications will become an important factor. In general, there is less contamination in source-separated material, but collection is more labor-intensive, and many communities are choosing to sort all materials at a central materials recovery facility (MRF). In many regions, markets for materials are not keeping pace with the volume collected, and it is expected that buyers will tighten specifications; as a result, vendors will no longer have assured markets, and will be competing to sell materials. As the specifications for recovered materials become more restrictive, recovery program managers must consider buyer specifications carefully when choosing collection and sorting systems, especially where large capital expenditures are involved. 13-6 Future Changes in Waste Composition In terms of solid waste management planning, knowledge of future trends in the composition of solid wastes is of great importance. For example, if a paper-recycling program were instituted on the basis of current distribution data and if paper production were subsequently eliminated, such a program would more than likely become a costly white elephant. Although this case is extreme, it nevertheless