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close this bookGATE - 1/95 - Waste Water: Resource Management and Environmental Hygiene (GTZ GATE, 1995, 56 p.)
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View the documentSetting new priorities
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Setting new priorities

Unsatisfactory wastewater disposal endangers health and is jeopardising the vital resources of water and soil

Developing countries must invest more funds in the disposal of liquid and solid waste. The return of epidemics which we thought belonged to the past can also be attributed to the fact that this part of public infrastructure has been neglected particularly in urban agglomerations. Dr. Klaus Erbel, Head of GTZ's Division "Water, Waste-Management and Protection of Natural Resources" explains to gate how this must be a key activity of development cooperation.

gate: Even the United Nations Water Decade did not trigger off a decisive improvement in wastewater disposal in many developing countries. 90 to 95 % of all communal wastewater is discharged unpurified into rivers and lakes. The pollution load has been overstepped in many instances. Has the construction of sanitation facilities been underrated in infrastructural investments by the affected countries and in bilateral and multilateral cooperation for development?

Erbel: We repeatedly observe that governments and local authorities in many countries only place a low priority in investments in sanitation infrastructure. This applies both to wastewater purification and to solid waste disposal. Whether minister or mayor, it is always better for his/her image to inaugurate a new road or new waterworks rather than to celebrate the completion of a certain number of kilometers of sewerage canals or latrines.

Development cooperation is usually a response to applications for projects, and so it is difficult to instigate action, even though we are of the opinion that the cleaning up of waters and the reduction of health risks should have highest priority. Some newly industrialising countries are beginning to rethink matters.

Too expensive

gate: What is the role of appropriate technology in wastewater disposal? Centralised plants like those in urban agglomerations in industrialised countries can hardly be a model for countries of the South.

Erbel: Centralised systems which collect flushed sewage are not always appropriate, simply because they have become far too expensive in most towns. This is particularly the case in regard to the so-called flushing or mixed sewage system containing both rain water and polluted water, rather than to the sewage treatment plants themselves. Houses usually have to be connected to the drinking-water supply in order to have enough water to flush away the pollutant substances. In many (arid) countries such water connections don't exist. Appropriate technology in this instance consists of multi-chamber cesspits which are regularly emptied and in which a large amount of the wastewater (e.g. washing water) can seep into the underground without causing any extensive environmental pollution.

"Polluter pays"

gate: Enormous amounts of money are necessary for sewage disposal. How can this money be raised? How can the "polluter pays" principle be applied in countries of the South when it is often difficult to apply in industrialised nations?

Erbel: In view of the limited funds available from development aid donors on the one hand and the countries' own governments and authorities on the other, there is no medium- or long-term alternative to the principle that whoever discharges wastewater into the system also has to pay for the treatment of this water.

We recommend that, first of all, the "polluter pays" principle should apply to large and small-scale industries and that information and sensitisation campaigns should raise the individual citizen's awareness that they also will have to contribute to the protection of their own environment via charges coupled to the water supply tariffs.

Successful project

gate: Can you state any examples of successful projects in which GTZ has cooperated with developing countries on wastewater treatment? What was the reason for the success? What conditions were right?

Erbel: An example of a successful project in TC Advisory Services on wastewater is the support for the "Office national de l'assainissement" (ONAS) in Tunis. The framework conditions were indeed very favourable:

Both the government and also the public were aware of the problem of protecting the environment, above all the water resources, because Tunisia earns much of its foreign exchange from tourism and tourism demands clean beaches and safe water.

Steady economic growth and substantial financial support from numerous multilateral and bilateral donors made it possible to invest in environmental protection.

The ONAS' personnel is very motivated. The low staff fluctuation rate means that the transfer of knowledge through our project and the contents of this transfer could be well-accepted and continuously applied.

Project success is also due to the fact that the partner organisation was an active and constructive partner in drawing up solutions. Training of expert personnel was supported by cooperation with the local engineering college (EcNational des Ingeurs Tunesiens ENIT). The long-term assignment of highly qualified experts from Germany and the development policy sensitivity led to the development of a situation of trust and confidence right up to ministerial level. The resulting political support meant in turn that the project received all the necessary manpower administrative and financial support it required.

gate: Faced with the global shortage of water, wastewater has become a valuable raw material which must be recycled. What action is necessary to this end?

Erbel: I feel it is particularly necessary to recycle purified or at least partly purified wastewater for use in irrigation and for re-use in industry. Irrigated farming systems using recycled water must, however, continuously monitor the quality of water, and this is not always possible in many countries.

Focus on urban regions

gate: Industrial expansion is causing additional sewage disposal problems in urban conglomerations. Should development cooperation set a new priority here?

Erbel: In my opinion, environmental problems in many urban conglomerations are taking on such proportions that development aid organizations will soon receive a flood of applications for support. Just a few cases of epidemics due to inadequate waste disposal are enough for this to take place. Cooperation for development has two choices: either to capitulate in the face of the dimension and frequency of such problems and the funding they demand, or, indeed, making it one of its key activities. Rural development has been a high priority area to date. But it is now becoming clear that these approaches have not led to any serious reduction in the rural exodus or halted urban growth. For this reason alone, cooperation for development must begin to address the issue of the quality of life in large conglomerations, an approach which will probably be more effective in reducing the poverty of wide sections of the underprivileged population. Numerous third world countries will have to assure better living conditions for the urban population, which bears the main brunt of national productivity, with or without external assistance.


Les investissements dans le domaine de l'cuation des eaux us figurent aux tous derniers rangs sur la liste des prioritde nombreux pays en dloppement. Dans l'interview donnau GATE par Klaus Erbel, Chef de division a GTZ, celui-ci pronostique un accroissement des probls environnementaux dulant de systs d'assainissement dcients dans les agglomtions urbaines des pays en dloppement. C'est pourquoi, ce secteur devrait devenir un domaine d'action prioritaire de la cooption au dloppement.


En muchos paises en des arrollo, las inversiones en eliminacie aguas residuales ocupan uno de los os lugares en la lista de prioridades. Klaus Erbel, jefe de divisie la GTZ, pronostico en una entrevista con gate que los problemas ambientales derivados de deficiencias en materia de eliminacie aguas negras aumentarian en los grandes centros urbanos de los paises en desarrollo. Por lo tanto, deberia darse mayor prioridad a este sector en el marco de la politica de desarrollo.