CHAPTER 15 ENVIRONMENTAL CONCERNS: WASTES AND POUUTION. 493 37.5% 179% 24% 28% 63% 6.7% 63%67% FIGURE 15.5 Paper and paperboard Ferrous metals Types and percentages of municipal Yard wastes Plastics and leather McKinney, M. L, and r.M. Glass Food wastes Miscellaneous edition. Sudbury, MA: Jones greater efficiency is needed in collecting the wastes so that more money can be pent on environmentally sound disposal. Traditionally, municipal wastes have been collected at the curb or alley by crews of three people and a large truck However, experience has shown that crew size, truck size, and special-feature trucks-like those that can be operated by a single person or those with different storage compartments for separating the trash-can improve efficiency and reduce sanitary landfills waste disposal site cost(see Figure 15.6). Moreover, the collecting and transporting of trash through on land suited for this pipelines hydraulically and/or pneumatically(the method used at Disney World) purpose and upon can make collection even more efficient which waste is spread Currently most municipalities dispose of their wastes in sanitary landfills, sites layer of day or plasic judged suitable for inground disposal of solid waste. However, many of these foam each day municipal landfills are filling up, and the availability of land suitable for new landfill sites near cities is quickly disappearing. Disposal of municipal solid waste on unsuitable land can result in the contamination of groundwater (water found in the ground), which may be the community's only source of drinking water. To meet integrated waste the need for better management of solid waste, many communities have adopted app an integrated waste management approach. This approach combines the fol- lowing four methods in a way best suited to local needs and capabilities: (1) sani. dispin ofsold tary landfills, (2)incineration, (3)recycling, and (4)source reduction. 2 sanitary lo incineratiOn Sanitary landfill Prior to the mid-1970s much of the solid waste in the United States was simply source reduction placed in a hole in the ground with little thought given to the underlying soil type