Tab 13-3 Typical physical composition of residential MSw in the United States in 1990 Percent by weight olid was Solid waste Solld waste as collected as collected plus food omponents now excluding waste recyc food waste that components now and food waste is ground up" that is ground up that is ground up Food wastes 9,4 8.0 33.8 35.8 Leather 17.3 172 2.0 2,0 1.8 Glass 9.0 Tin cans 0.5 Other metal Total 0o.0 00.0 100.0 100.0 Tab 13-4 Typical physical composition of residential MSW excluding recycled materials and food wastes discharged with wastewater (1990) Percent by weight United States c Range Packaging materials Davis, California OrganIc Food wastes 6-18 9.0 6 34.0 5060 33.1 Plastic 12-16 Rubber 0→2 Leather Yard wastes Wood 4-8 Glass 4-12 8.0 20-30 5.8 Tin car 2-8 6.0 6-8 3.9 Aluminum 0.5 2-4 0.4 Other metal 3.0 3.6 Dirt, ash, etc 06 30 0.5 Tota 100.0 100.0 13-4 Determination of the Composition of Msw in the Field Because of the heterogeneous nature of solid wastes, determination of the composition is not an easy task. Strict statistical procedures are difficult, if not impossible, to implement. For this reason, more generalized field procedures, based on common sense and random sampling techniques, have evolved13-7 Tab 13-3 Tab 13-4 13-4 Determination of the Composition of MSW in the Field Because of the heterogeneous nature of solid wastes, determination of the composition is not an easy task. Strict statistical procedures are difficult, if not impossible, to implement. For this reason, more generalized field procedures, based on common sense and random sampling techniques, have evolved