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Chapter 8 Lessons Learned and Recommendations
Through the Bauniabad study, we learned the following lessons and came up with the recommendations.
8.1 Needs for Appropriate Systems
Lessons Learned
The study revealed that unless appropriate systems are adopted, WS projects cannot be sustainable. In Bauniabad, two
systems: (i) hand pumps for water supply and (ii) alternate pit latrines were equipped in all houses. The hand pumps
did not work as the water table of the area in one of the fastest growing capital city, Dhaka, lowered to almost beyond
manual pumping level. Since there was no provision for supplying piped water to poor settlements like Bauniabad
where billing system did not exist, the people had to walk for long distance to a pump that was barely working to
collect their water and/or had to use contaminated pond water. The alternate pit latrines also did not work well
due to poor maintenance and improper use of the pits. It indicates that appropriate systems should be considered,
taking into account various issues including technological, financial, cultural and social factors. For instance, people
did not want to remove sludge from their latrine pits by themselves because they were not socially accustomed to
do so directly by themselves. There was no committee or other formal system to empty the contents of the pits. The
commission fees for sludge removal were too high for them and both pits were almost full with liquid especially in
the rainy seasons. Moreover, due to the severe space constraints, the people could not use the pits in turn as required.
In order to address all such issued, a multidisciplinary team, involving scientific/engineering, economic, cultural and
social disciplines as appropriate, is required.
The biogas based sewerage system worked relatively well in Bauniabad. The factors for success and its replicability
should also be investigated by this multidisciplinary team. The main factors may be: (i) the new design of the system
based on people’s sanitation needs and developed through people’s participation, (ii) relatively small-scale, gravitybased
waste water (excreta) collection system, which can only be applied to densely populated areas with slopes
that are of a certain angle (difference of height), and (iii) minimum space used for the system because the plant were
constructed underground.
The installed piped water system provided safe drinking water to the people. But the institutional and water safety
issues were poor until recently when an action research has started again.
Recommendations
- Adoption of an appropriate system is the key for successful WS projects. The system should be selected with not
only technological considerations but also economic, cultural and social considerations. The following factors
should be considered when we adopt appropriate systems.
• Engineering performance (pollution removal rate etc.);
• Initial costs for installation;
• Operation and maintenance of the system and its associated costs;
• Community management mechanism(s) to construct and operate the system; and
• Social and cultural acceptability of the system.
- A multidisciplinary team may need to be established to consider appropriate technologies for a specific site.
This team should document the factors as to why the technologies are adopted in the specific site and investigate
replicability of the technologies.
8.2 Collaboration with Scientific and Engineering Experts
Lessons learned
In considering technological and engineering aspects of the system, particularly when the technology is not the
conventional one, it is important to involve competent scientific and engineering experts. They should be continuously
kept involved during the operation stage as well. In the case of biogas based sewerage system in Bauniabad, the
research and development (R&D) stopped before its completion. This created the following problems in engineering
design and operation of the projects.
- Quantity of inflowing waste water was much bigger than originally planned, which caused insufficient retention
time in the biogas chambers, leading to both a lesser removal rate of pollutants and generation of biogas.
- Lack of effluent monitoring resulted in the delay to find heavily polluted discharge, leading to the inability to take
the necessary measures in time to combat the adverse environmental consequences. Engineering design was
based on the idea that no maintenance was required, which made appropriate maintenance, especially periodic
cleaning of biogas chambers and removal of sludge, quite difficult.
- Biogas generation optimization was to be included in the second phase of the R&D after meeting the immediate
sanitation need of the people. However, the second phase did not occur. More efficient biogas generation and
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