Abstract:
Conventional Sewerage System (CSS) is a traditional system, which is generally used in
almost all countries of the world. Conventional Sewerage System(CSS) is costly which is
not affordable in low-income countries. In this aspect, small bore sewerage (SBS) system
is recently used technology which may be an alternative to CSS in the developing
countries. This technology is relatively little known, but it is extensively used in
Australia, Africa, and U.S.A.
The purpose of this project study was to make a comparison between the CSS and SBS
system with a view to examine the suitability of SBS system as an alternative to
wastewater management option and it's applicability in small township. Comparison was
made of on the basis of technical and economic point of view. Proper design of both the
systems and cost analysis of those systems were examined and compared using the data
available. The project also represents an analysis of interaction of various parameters,
which cause changes of cost in both systems.
The study area is the newly developed planned urban area named Lake City Concord in
Namapara, Khilkate, in Dhaka. From the cost analysis and graphical representation of
CSS and SBS system it can be visualized that in the SBS system cost saving are 28.71%
in earth excavation (i.e. only cost difference between the earth excavations of both
system), similarly 51.52% in sewer, 48.40% in manholes and cleanouts, and 80.23% in
wastewater treatment. Finally, the total capital cost reduction 28.51 % (i.e. grand total cost
difference between CSS and SBS system) in the SBS system than the CSS. Also outcome
of the study is that in the CSS capital cost per person is Tk 1320.60. Whereas in the SBS
system capital cost per person is Tk 1027.65.
