MASTER'S THESIS - SuSanA

4 Presentation of technologies for rural areas
4.4.3 Conclusion about appropriatness of presented technology
The presentation of the technology does not claim to be complete but shows that there are many different
technologies existing depending on the different specialities and requirements of each site where they shall
be implemented. The higher the requirements for the treatment of wastewater and feacal sludge are, the
more complex the technology gets. It has been noted that the used terms for the technologies can be
different in the literature and that some technologies show only little differences. This shows that
technologies are adapted to the needs, but not always developed following a certain structure.
Technologies consit of the different components for collection, transport, treatment and discharge or reuse.
But in reality, it is not possible to allocate each technology or component to one purpose. Often, the
different purposes can be combined in one treatment unit, like collection and pre-treatment or tretment
and discharge. In some cases, no transport is needed or pre-treatment and discharge are sufficient for the
considered site and no secondary treatment takes place.
As the technology presented by the GIZ hired consultant Martin Wafler shows only a little selection of
treatment technologies and its components, this chapter should give a broughter overview over
technologies that are in general considered in the literature as low-cost and/or appropriate for rural areas.
It was shown that several technologies fulfil different purposes for the wastewater handling and its
treatment.
Main criteria against a technology are high investment and O&M costs as well as difficult construction,
operation and maintenance. Necessary energy supply can be a criteria for exclusion, depending on the site
and the actually needed amount of electricity. Technology without electricity consumption is always
preferred.
For areas where no or only little treatment is necessary (remote mountain areas with scattered houses and
fresh drinking water from the mountains, without financial means for sanitation projects), the following
simple solutions can be considered to prevent uncontrolled open wastwater discharge:
• simple pits
• septic tanks combined with soak pits
In these areas where people often empty their pits themselves, people should get training and information
about how to empty their pits savely. In best case, personal protection equipment, like gloves, should be
distributed.
Areas, where treatment of wastewater is necessary, the technology selection depends, amongst other
things, on the required effluent quality and the available area. In any case, construction and O&M should be
low, the operation simple and the processes stable.
On-site solutions for areas with higher effluent requirements can be the implementation of
• septic tanks, that get emptied by sucking vehicles or
• small constructed wetlands for every household or cluster of houses.
Improvements of the septic tank, like the baffled septic tank or the installation of an anaerobic filter are
possible.
If a centralised treatment will be planned, constructed wetlands and ponds (combined with pre-treatment)
are options that are simple to construct, to operate and maintain and where energy supply is not
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