b. Sanitary Landfills.
(1) The sanitary landfill is the most common and preferred refuse disposal.
The principles are simple. There are two landfill methods commonly used.
(a) Area method. This method is used when the terrain is unsuitable for
the excavation of trenches in which to place the wastes. Operationally, the wastes are
unloaded and spread in long, narrow strips on the surface of the land in a series of
layers that vary from 16 inches to 30 inches. Each layer is compacted during the
course of the day until the thickness reaches a height varying from 6 feet to 10 feet. At
that time, and at the end of each day's operation, a layer of cover material is placed
over the completed fill.
(b) Trench method. Refuse is dumped into a trench, compacted, and
The trench is dug approximately 600 feet long, 10 feet wide, and 6 feet deep. The earth
from the trench is used to construct a ramp on the windward side of the trench (this is
done to minimize blowing of refuse). Between loads, the trash is compacted by a
bulldozer. Compacting reduces the volume of refuse to one-third or less of its original
volume. The compacted trash is covered with a layer of dirt, which is compacted again.
This procedure is repeated until alternate layers of compacted trash and dirt fill a
section of the trench (see figure 1-7). At the end of each day, when a section of trench
has been filled with compacted refuse and graded, the top, side, and end of the section
are covered with earth. The cover is 2 feet at the top and 1 foot at the side. Just
enough cover on the working face or end is required each day to confine the refuse and
to form a seal. The compacted refuse is sealed once a week or more often by covering
the working face with 1 foot of well-compacted earth. Sealing the refuse into cells
provides a firebreak, controls odors, and prevents rodents from reaching the refuse.
The last section of each trench should be covered with at least 2 feet of earth.
Additional operational requirements may be specified in applicable Federal, State or
local regulations. These requirements must be met to ensure compliance with these
regulations.
(2) Sanitary fills have advantages not common to other methods of refuse
disposal.
(a) Apart from truck drivers, one man with a bulldozer and a dragline
bucket may be all that is needed at a small landfill.
(b) They may not require segregation of refuse.
(c) They can accommodate large fluctuations in the daily accumulation
of refuse without additional personnel or equipment. Approximately 1 acre per year is
allowed for each 10,000 men when the fill is to be 6 feet deep.
MD0162
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