Die Deponie in einer ökologisch orientierten Volkswirtschaft

Landfill strategies of a society are based, consciously or unconsciously, on ethical demands. An ecologically orientated economy is challenged to control its metabolism according to the principle of precaution. With regard to landfilling of solid wastes, the principle of precaution can be interpreted as follows: The material should have properties similar to those of the earth crust, that is natural sediments, rocks, minerals or soils. Each generation should handle its waste in a way that these properties are reached within the producers lifespan. In industrialized and affluent societies the landfills of the youngest past do not meet these criteria. They are biological and chemical reactors which have to be controlled at present and by future generations, most probably at least several hundreds of years to prevent detrimental emissions to the biosphere. The most problematic substances are the organic components which endanger the groundwater quality. With regard to their resource potential these heterogeneous mixtures of a wide variety of substances (for example municipal solid waste, industrial waste) are of minor or no value. It becomes evident that such landfill types are in contradiction to the principle of precaution. An ecologically orientated landflll strategy should be based on models of modern geology. Landfills should be understood as anthropogenic sediments which undergo diagenetic processes. The recorded history of different geogenic sediments in geological times gives informations on their physical and chemical transformations under different boundary conditions. From this one can deduce quality criteria for anthropogenic sediments. A first evaluation of two products of waste treatment plants, namely bottom ashes and filter dust from incineration of municipal solid waste, shows that these criteria are not yet met. It follows that on a short-term range a strong improvement of process engineering and a capacity increase of waste treatment plants (mainly separate collection and thermal treatment) is indispensable. However, projects of new waste treatment plants in densely populated regions are very often rejected by the people of the community which is selected. On a long-term range only an adaptation of the whole economy to the above mentioned criteria is ecologically reasonable. Such an adaptation can not be achieved solely by technical means. It touches severely the existing hierarchy of values of a national economy. Therefore it is necessary to combine the methods of political and social sciences with those of the natural and engineering sciences to transpose landfill strategies into practice.