ramp is covered with earth taken from ahead of the 
base of the ramp. The following day’s refuse will 
be spread and compacted on the slope formed by the 
covering over of the first day’s refuse, and covered 
by further excavation in front of the base of the 
advancing slope. \ windrow of earth built before 
placement of refuse along one or both edges of that 
part of the slope that is above original ground level 
is frequently desirable. This will lessen the scat- 
tering of paper and boxes by the wind, and will help 
to contain the working area and to facilitate cover- 
ing of the side slopes. Earth placed as cover on 
the ramp should be at least 6 inches in depth after 
compaction, and the cover at the final level should 
be 2 feet thick. 
In Swamps, Marshes, and Low Areas. The same 
basic method may be used in most of the locations 
where it is impossible or undesirable to obtain 
cover material from the base of the slope. In low 
or swampy locations, a moving slope may be built 
into the area to be filled, working out from a natural 
bank or a constructed ramp. Here the refuse will 
necessarily be deposited at the top of the ramp. 
The slope should be gradual enough to allow the 
tractor to spread and compact the refuse over its 
entire surface. Frequently a foundation of waste 
building material or other material is first con- 
structed into the swamp or marsh. On this founda- 
tion, the working slope is then advanced to fill 
the area to the desired level. Earth for cover is 
obtained from nearby elevations or is brought in by 
truck. In some situations, cover is obtained from 
in front of the working slope by use of a dragline. 
Thus a low area may be raised as shown. 
In Valleys and Ravines. Valleys and ravines 
are frequently chosen as landfill sites. When 
these are of considerable depth, they should 
be filled in layers with each layer beginning at 
the higher end of the ravine so that the natural 
drainage will not be obstructed. Earth cover for 
the first layer, as it moves through the length of the 
ravine, may often be obtained from ahead of the 
base of the advancing slope. However, cover for 
subsequent layers or “lifts” will usually be ob- 
tained from the sides of the ravine. 
Under some circumstances it may not be desira- 
ble to extend the first layer of cells through the 
whole length of the ravine before construction of 
the upper layers is begun. In this event, the first 
layer of cells may be constructed only a relatively 
short distance from the upper end of the ravine. In 
longitudinal section this would give the appearance 
of a series of steps when the top layers are com- 
pleted. This procedure would permit a portion of the 
cover for the upper layers to be obtained, if neces- 
sary, from the bottom of the ravine ahead of the 
face of the first layer; then brought up the ramps of 
the other layers to the operating level. When the 
upper layers have been completed, the bottom layer 
can be extended a short distance and successive 
layers built over it in the same manner. One advan- 
tage of this method of operation in ravines is the 
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