Section 7:
SANITARY LANDFILLS
7.1 Introduction. Sanitary landfilling is the most acceptable and flexi
method for ultimate disposal of solid waste. Other techniques such as la
spreading and surface impoundments also provide ultimate waste disposal,
these methods are generally more suited to liquid wastes and sludges. Oc
disposal is not practiced primarily because of the high transport costs a
the concomitant environmental problems. Incineration, composting, and ot
processes are often called disposal methods, but cannot be considered as
means for ultimate disposal of wastes, since residue from these processes
require disposal on land.
This section presents current technology for the design of sanitary
landfills and related engineering considerations.
7.2 Site Selection. When evaluating alternative sites for a sanitary
landfill, major technical and economic factors must be considered:
7.2.1 Site Life and Size. The site life is determined by the area of th
site, cover soil availability, quantity and characteristics of the solid
waste to be delivered, the landfilling method, and the projected in-place
density of the compacted solid waste. The usable area of the site is
determined by excluding from the gross area land for buffers between the
site boundary and the filling area, access roads and soil stockpiles not
located on the fill surface, and onsite structures and equipment storage
areas. Typically, the usable fill area ranges from 50 to 80 percent of t
gross area. Figure 13 is a formula for estimating landfill area
requirements.
7.2.2 Location in Relation to Waste Generation Centers. The landfill sit
should be located as close as possible to areas of solid waste generation
This will reduce haul costs and total exhaust emissions from haul vehicle
7.2.3 Topography. Landfills can be located in a wide range of terrain,
including depressions, areas with relatively flat terrain, and canyons.
sites located in depressions (e.g., abandoned coal strip mines, clay or
gravel pits, and natural depressions) generally have little or no cover s
available onsite. Therefore, site capacity for solid waste is reduced by
the area of land needed for cover soil. Also, runoff management at
depression areas is more critical. Offsite runoff must be diverted aroun
the proposed landfill area. Runoff from incident precipitation in the
filling area must be controlled to prevent contact with deposited wastes.
If the runoff cannot be evaporated or percolated into site soils, it must
pumped to an offsite drainage channel.
5.10-51
Previous Page
