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As the supply was not continuous, the risks of not maintaining the pressure balance in the system existed, leading
to the possibility of the safely pumped out water becoming contaminated. In addition, as mentioned above, since
the pressure balance in the system is not stable, there is a possibility of the contaminated water to back flow
into the system, especially when a tank is constructed around a tap as shown in Photo 5.1. The possibility of the
back flow occurring happens when the water level goes above the tap, which occurs quite easily when a tank is
constructed around a tap and not beneath it, leading to the contamination of the distribution system. The storage
tanks between the taps and storage containers were introducing highly unacceptable contamination risks to the
safely supplied drinking water.
It may be pointed out that the main distribution system with primary (from the pump) and secondary (inside
the blocks) branches were installed by DWASA. Usually the connections are made by DWASA after the users
make payments. However, most of the households did not pay the connection fees and made illegal connections
themselves which extended over a few meters. The illegal connections that led outside the blocks included tertiary
branches from Block A, which were more than 30 m long and were not done properly. When the connections are
not done properly, another form of contamination may occur through leakages, where pollutants may be sucked
inside the system by negative pressure created in the system when a pump starts. This problem poses a serious
threat, as there is no provision for chlorination or disinfection of water.
Pt. Outside-1 in Table 5.2 refers to an illegal tap/connection as mentioned above, installed by the people of
the neighborhood outside the blocks, which was further down the distribution system. There was also a big
underground tank installed in one of the neighborhoods outside the blocks by an NGO to store and supply water
to several families (Pt. Outside-2). The tap supplying water to the underground tank was connected to the same
piped distribution system that was connected to the taps supplying water to the residents inside the blocks. Many
people used the underground tank water for drinking and all kinds of washing purposes. However, unacceptable
high levels of contamination were detected at both the illegally installed tap/connection and the legally stored
underground tank outside the blocks (Pt. Outside-1 and Outside-2). After discussions with the users of the
underground tank, it was revealed that there is no mechanism for the regular cleaning of the tank.
5.5 Cost Implication
A summary of the reported costs invested in water supply for drinking purposes by the people surveyed inside
the blocks is presented in Figure 5.3. Invested installation costs by the people for various options during different
periods are presented in detail in Table A-4.2 in Appendix 4.
It is estimated that during the period of hand pump use, the cost of a hand pump and deep-set tube well was
about $US 200. In most cases the pumps were installed free by Concern before 1995. In Figure 5.3, the maintenance
and repair costs are not included, as the residents shared the minor repair costs for hand pumps, and most of the
respondents could not remember how much they spent. They did not do any major repairs, as the costs associated
with doing so were equivalent to that of installing a new pump. According to the focus group information,
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