The search for landfill sites - requirements and implementation in Lower Saxony, Germany

Abstract

In Germany, landfilling and incineration are the main techniques for the disposal of waste. However, due to humid climatic conditions, leakage of contaminated water from landfills into the subsurface poses a considerable threat to the environment. Therefore, the German states require high safety standards for the construction of a landfill. Emphasis is put on the presence of natural geological barrier rocks. Clay and silts, claystones and siltstones are best suited to meet the requirements defined in legal waste regulations. With regard to retardation capacity, thickness is considered of higher importance than hydraulic permeability. Suitable areas have to be reduced by legally excluded areas. A site search program in Lower Saxony revealed that only 1% of the total state area falls into the best suitability category. Geoscientific investigations on the remaining suitable areas have to become more detailed in the search progress. Geographical information systems (GIS) are the most adequate tools to work on all involved data and to present and outline the results. GIS make the results transparent and understandable to the public. These investigations are a necessary part of the environmental impact assessment which is obligatory for a landfill site's construction. Criteria catalogues take all important aspects of the search process into consideration and help to find the most suitable site.