15 Disposal of solid Wastes and Residual matter le safe and reliable long-term disposal of solid waste residues is an important component of integrated waste management. Solid waste residues are waste components that are not recycled, that remain after processing at a materials recovery facility, or that remain after the recovery of conversion products and/or energy. Historically, solid waste has been placed in the soil in the earth's surface or deposited in the oceans. Although ocean dumping of municipal solid waste was officially abandoned in the United States in 1933, it is now argued that many of the wastes now placed in landfills or on land could be used as fertilizers to increase productivity of the ocean or the land It is also argued that the placement of wastes in ocean trenches where tectonic folding is occurring is an effective method of waste disposal Nevertheless, landfilling or land disposal is today the most commonly used method for waste disposal by far. Disposal of solid waste residues in landfills is the primary subject of this chapter The planning, design, and operation of modem landfills involve the application of a variety of scientific, engineering, and economic principles. The major topics covered in this chapter include: (1)a description of the landfill method of solid waste disposal. including environmental concerns and regulatory requirements:(2) a description of types of landfills and landfilling methods:(3) landfill siting considerations:(4) landfill gas management; (5) landfill leachate control:(6) surface water control: (7 landfill structural characteristics and settlement:( 8)environmental quality monitoring:(9) the layout and preliminary design of landfills: (10) development of landfill operation plan:(11 landfill closure and st-closure care: and(12)landfill design computations 15-1 The Landfill Method of Solid Waste Disposal Historically, landfills have been the most economical and environmentally acceptable method for the disposal of solid wastes, both in the United States and throughout the world. Even with implementation of waste reduction, recycling, and transformation technologies, disposal of residual solid waste in landfills still remains an important component of an integrated solid waste management strategy Landfill management incorporates the planning, design, operation, closure, and postclosure control of landfills. The purposes of this section are(I)to introduce the reader to the landfilling process,(2)to review the principal reactions occurring in landfills, (3) to identify environmental concerns associated with landfills, and(4)to review briefly some federal and state regulations governing the disposal of solid waste in landfills The Landfilling process Definition of Terms. Landfills are the physical facilities used for the disposal of residual solid wastes in the surface soils of the earth. In the past, the term sanitary landfill was used to denote a landfill in which the waste placed in the landfill was covered at the end of each day's operation. Today. sani refers to an engineered facility for the disposal of msw designed and operated to minimize nealth and environmental impacts. Landfills for the disposal of hazardous wastes are called secure landfills. A sanitary landfill is also sometimes identified as a solid waste management unit. Landfilling is the process by which residual solid waste is placed in a landfill. Landfilling includes monitoring of the incoming waste stream, placement and compaction of the waste, and installation of landfill environmental monitoring and control facilities. The term cell is used to describe the volume of material placed in a ndfill during one operating period. usually one day. a cell includes the solid waste deposited and the daily cover material surrounding it. Daily cover usually consists of 6 to 12 in of native soil or alternative ing period. The purposes of daily cover are to control the blowing of waste materials, to prevent rats, flies, and other disease vectors from entering or exiting the landfill; and to control the entry of wate nto the landfill during operation.1 15 Disposal of Solid Wastes and Residual Matter The safe and reliable long-term disposal of solid waste residues is an important component of integrated waste management. Solid waste residues are waste components that are not recycled, that remain after processing at a materials recovery facility, or that remain after the recovery of conversion products and/or energy. Historically, solid waste has been placed in the soil in the earth's surface or deposited in the oceans. Although ocean dumping of municipal solid waste was officially abandoned in the United States in 1933, it is now argued that many of the wastes now placed in landfills or on land could be used as fertilizers to increase productivity of the ocean or the land. It is also argued that the placement of wastes in ocean trenches where tectonic folding is occurring is an effective method of waste disposal. Nevertheless, landfilling or land disposal is today the most commonly used method for waste disposal by far. Disposal of solid waste residues in landfills is the primary subject of this chapter. The planning, design, and operation of modem landfills involve the application of a variety of scientific, engineering, and economic principles. The major topics covered in this chapter include: (1) a description of the landfill method of solid waste disposal, including environmental concerns and regulatory requirements; (2) a description of types of landfills and landfilling methods; (3) landfill siting considerations; (4) landfill gas management; (5) landfill leachate control; (6) surface water control; (7) landfill structural characteristics and settlement; (8) environmental quality monitoring; (9) the layout and preliminary design of landfills; (10) development of landfill operation plan; (11) landfill closure and post-closure care; and (12) landfill design computations. 15-1 The Landfill Method of Solid Waste Disposal Historically, landfills have been the most economical and environmentally acceptable method for the disposal of solid wastes, both in the United States and throughout the world. Even with implementation of waste reduction, recycling, and transformation technologies, disposal of residual solid waste in landfills still remains an important component of an integrated solid waste management strategy. Landfill management incorporates the planning, design, operation, closure, and postclosure control of landfills. The purposes of this section are (1) to introduce the reader to the landfilling process, (2) to review the principal reactions occurring in landfills, (3) to identify environmental concerns associated with landfills, and (4) to review briefly some federal and state regulations governing the disposal of solid waste in landfills. The Landfilling Process Definition of Terms. Landfills are the physical facilities used for the disposal of residual solid wastes in the surface soils of the earth. In the past, the term sanitary landfill was used to denote a landfill in which the waste placed in the landfill was covered at the end of each day's operation. Today, sanitary landfill refers to an engineered facility for the disposal of MSW designed and operated to minimize public health and environmental impacts. Landfills for the disposal of hazardous wastes are called secure landfills. A sanitary landfill is also sometimes identified as a solid waste management unit. Landfilling is the process by which residual solid waste is placed in a landfill. Landfilling includes monitoring of the incoming waste stream, placement and compaction of the waste, and installation of landfill environmental monitoring and control facilities. The term cell is used to describe the volume of material placed in a landfill during one operating period, usually one day. A cell includes the solid waste deposited and the daily cover material surrounding it. Daily cover usually consists of 6 to 12 in of native soil or alternative materials such as compost that are applied to the working faces of the landfill at the end of each operating period. The purposes of daily cover are to control the blowing of waste materials; to prevent rats, flies, and other disease vectors from entering or exiting the landfill; and to control the entry of water into the landfill during operation