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DEZA-SHA
MissionMaldives
Final
report
General Conclusions:
After our
assessment the following conclusions can be made:
 Fundamentally
the existing rainwater collecting system was used since centuries. It should
not be replaced by any other system, but the system has to be improved (e.g.
enlarge the capacity of storage system).
The
damaged and lost HDPE tanks have to be replaced and the total storage
capacity has to be checked for each island. It should be calculated for each
village. For further calculation the water need per person and day should be
estimated at about 3 - 5 liter drinking water. The capture area to fill up
the rain water tanks has to be considered as well.
Only
in case of disasters or in case of water shortening at the end of a dry
season the desalination plants now ordered or already in place should be
available. The high costs (app. 5 euro cents/liter) and the technical
assistance and support of these installations which asks educated specialists
are good arguments for not replacing the established rain water system.
The
groundwater wells should be cleaned now after the tsunami. For this purpose
there should be on every island (village) at least one small gasoline- or
diesel gasoil pump unit. To handle this pump unit a
team should be instructed, so that they can go to every well in the village
to clean it. This action should be repeated twice every year.
When the well is empty it should be brushed out and chlorinated. In future
this action should be repeated twice a year.
After
cleaning the groundwater wells the water is expected to bee still too salty.
This will probably last at least until the end of the next rain season. To
check this it needs a monitoring program to control at least the salinity.
For this purpose there are periodical conductivity measurements necessary. If
the values reach a conductivity of about 500 – 800 µS/cm the water can be
used for cooking, hygiene and washing if it’s colorless and clear.
The
people know well their duties, i.e. cleaning the roofs before rainy seasons,
cleaning the HDPE Tanks at least once a year, managing the available water,
etc. But authorities should make hygiene education on that purpose to show
how important all these duties are.
A
big problem is the whole sanitation situation, specially the system of
latrines with the septic tanks. The system with septic tanks and percolation
of the liquids causes groundwater pollution, the
same system with sewerage line into the sea is also not sustainable.
To prevent the groundwater from pollution the whole system of water
purification should be studied in detail.
We just want to mention, that most of the existing septic tanks were never
cleaned from the solids. This was not done, because people didn’t know what
to do with the solid stuff. So most of these tanks are no more in good
function.
For
long terms there should be installed monitoring programs to observe the
groundwater in the wells and also the quality of rainwater storage tanks.
This monitoring program can probably be executed by the responsible of help
point, help center or even hospitas.
The following parameters should be tested:
 Bacteriology
(E-Coli and Coliforms)
pH
conductivity
(µS/cm)
Chlorides
Ammonium
Nitrit
Possibly
Nitrat
For
further use of the groundwater and if possible even to ameliorate its quality
it is necessary to get more knowledge of the fresh water lenses below the
islands, “swimming” over the see water. It is also important to know what was
the effect of the tsunami wave flooded the islands and of the following
infiltration of sea water from the surface into the groundwater.
To observe the development of the groundwater we recommend a feasibility
study regarding the groundwater situation in the Maldives.
For this purpose about 4 island should be selected (2 with septic tanks and
percolation into the groundwater, 2 with sewerage lines to the sea/or to a
small sewage plant with settling basins, e.g. planted with reed or some local
plants from where the purified water can be led to the sea, or if the quality
is more or less o.k. it can be soaked into the groundwater).
We recommend to work out a detailed program for such a hydrogeological feasibility study, with some drilled
boreholes and a monitoring program for groundwater quality.
Wednesday, January 12, 2004
DEZA WATSAN Specialists
Dr. Nik
Sieber and Dr. Willi
Finger
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