Environmental Engineering Reference
In-Depth Information
These problems persist so long as the areas are undergoing filling, which may
take many years or even decades.
The only practicable solution to the problem is to fill these areas as promptly
as possible, because there is little hope in the foreseeable future that waste
management practices will be much improved. The proposed refuse landfilling
reclamation scheme will achieve the objective of prompt filling. This will include
planned filling of sites so that the refuse hauling distances will be decreased. In
these selected areas filling will be as rapid as possible (as permitted by biolog-
ical degradation and consolidation constraints), thus minimizing the period of
unacceptable sanitation/public health/aesthetic conditions.
Structural Suitability of Completed Fill
Much of the literature on sani-
tary landfilling in the industrialized countries is concerned with the suitability of
the completed fill for use for sites for buildings. Such use has involved serious
problems because methane gas generation in the fill results in explosion hazards
beneath the building, with settling of the building due to settling/consolidation
of the fill, and with the difficulties in driving structural piling through the com-
pleted fill.
In the proposed refuse landfilling reclamation scheme for DCs, the problems
of methane gas and of fill settling appear to be eliminated due to the virtually
total biological degradation and total physical consolidation taking place in the
reclamation period because of the wetted condition in the fill during the rainy
seasons.
With respect to driving of piles, this should pose no significant problem
because of the limited depth of the fill, usually less than 2 meters. In addition,
where footings are used for foundations, because the fills are shallow, usually
it should be possible to place the footings to rest on the natural soil underlying
the fill.
No problems of the types described here arc known to have been reported in
Bangkok, despite the fact that much of the city (all built on former swamp/paddy
areas) has been filled with refuse to a depth of about 1.5 meters.
Overall Study Conclusions
The conclusions on economics are as follows:
The stabilized waste is suitable for fill material, which will be used for
developments such as parks, playing fields, light surface improvements,
one-story buildings with footings in soil below the fill, or structures on
piles. This is based on the study soils laboratory analyses that show that
the decomposed solid waste is similar in nature to inert fill material used
in Bangkok and based on experiences in Thailand and elsewhere where
swamps reclaimed with solid waste have been widely utilized for decades
for building development, with no known reported settling or structural
damage.
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Degradation of solid wastes deposited in low-lying areas with tropical mon-
soon climatic conditions probably occurs within two rainy seasons, and
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