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mentioned here that only two committees were trained on operation and maintenance of the R&D options under
Mr. Jainal, and the other committees were not trained as the research stopped abruptly. Mr. Jainal and a few of his
colleagues are taking the interest in addressing the problem within the case study.
6.6 Conclusions
The people of Bauniabad were closely involved in the selection of an appropriate technology for their basic
sanitation by comparing a few locally available demonstration sanitation options. They chose the biogas system
based on its cost and functional merits. The initial biogas facility used for research showed about 70% BOD removal
efficiency, and was cheaper than pit latrines or septic tanks in terms of per capita costs. Another positive aspect of
the system was that it had potentials for producing renewable energy, biogas, which is used for cooking.
However, the systems in general, were inefficient in the treatment of wastewater. The systems were exposed
to the following problems: (i) the original design of the biogas facility was developed by the research group on
the assumption that there would be less than 100 family connections per system, and later in the installation
phase (after 1999 by another NGO), the same design was used for connecting about 300 or more families, leading
to significant overloading of the systems. (ii) It was assumed that the biogas chambers would not require any
maintenance; therefore, there was no entry point in the chamber to check the inner workings of the chamber or
remove any sludge if necessary. Due to this limitation in not being able to conduct maintenance in the chamber,
the waste in the chamber started to solidify, and this eventually lead to the wastewater short circuiting through
the chamber. (iii) Piped water availability resulted in the discharge of high volumes of domestic wastewater into
the system, which diluted the wastewater and may have also contributed to the overloading of the systems. Finally,
(iv) community participation in the form of biogas committees were introduced to look after the maintenance
of the lesser complicated elements of the biogas based sewerage system, such as the connection pits, but these
committees did not function properly, or in some cases, did not function at all, and this lead to the maintenance of
such elements being neglected.
6.7 Further Steps to be Taken
Sanitation is the most complex and pioneering component of the projects. In Bauniabad, biogas based sewerage
systems have been developed and introduced as an option. Biogas based sewerage systems, like most technologies,
cannot be a universal solution; the solution will vary with location and time. It has shown the potentials for a
crowded urban population. Bangladesh and most of the developing countries are in need of appropriate solutions
for sanitation, and it is important that the research be completed in this regard. At least, the following research
activities may be considered in two phases:
i) Emergency phase
• Conduct action research to make the closed/back-flowing biogas based sewerage systems work under
emergency conditions, as the fish farms have closed the effluent discharge into the leased water bodies.
• The cost sharing scopes among the users and other local stakeholders for these emergency activities should be
studied.
• Minimum monitoring such as, wastewater influent and effluent flow rates, pH, nitrate, and COD with the use of
a field test kits should be considered.
ii) Technology development research
The following research activities may be carried out:
• Conduct sampling and testing of wastewater flow and quality, following proper and reliable methods to
understand the process and performance, in order to determine the problems of the existing options.
• To develop the capacity of local technicians and laboratories to be able to conduct accurate sampling and
wastewater testing.
• To carefully investigate how the sanitation options are affecting the surrounding water bodies. The ecological
implications of the options should be studied in the immediate and long-term perspectives. The actual reasons
for the fish farm problems should be investigated as well.
• Improvement of the engineering design of the biogas based sewerage system should be investigated, taking
into account the actual situations of influent and operation/maintenance of the biogas facilities.
• The local community should be trained and involved in planning, implementing, monitoring and operation and
maintenance of the option.
• The possible scopes of renewable energy production and reduction in greenhouse gas emission related to the
biogas based sewerage system should be studied.
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