Marcos Buser & Walter Wildi
The final disposal of highly toxic waste from industrial societies is generally associated with deep geological repositories of radioactive waste. Only rarely does attention also focus on chemical-toxic hazardous waste repositories. However, a large part of hazardous industrial waste in Europe is disposed of in such facilities. The vast majority of these repositories are located in former salt mines in Germany. Mines with more or less acute stability problems have been converted into backfill mines, in which the waste mixtures are used to support the instability of the mine cavities. Other chemically toxic hazardous wastes go to so-called underground landfills (in German: UTDs). In these more stable mines, problematic industrial wastes are simply stored in packages in disused mining areas. The difference between backfill mines and underground storage sites is not sharp and is becoming increasingly blurred in reality.
Deposits of chemo-toxic products sometimes make the headlines if problems are known. For example, when partial collapses of a mine, known as “massif break-up”, occur, causing, for example, significant earthquakes. Or when explosive gas mixtures are exploding and toxic gases are escaping from ventilation of a waste mine. Water penetration also receives occasional media coverage. Overall, however, the issue of toxic industrial waste disposal in abandoned mines does not particularly excite people’s minds. As long as the waste dumps are far enough away from housing areas, neither the society nor leading politicians are particularly interested in the issue.
However, an in-depth study and analysis of what is happening in the dozen or so hazardous waste mines, most of which are located in Germany, would also be of the utmost importance for the understanding and acceptance of geological repositories for radioactive waste. The following articles, which we will publish on our blog over time, therefore aim to provide a more comprehensive overview of the little-known world of underground geological disposal of the hazardous waste. We will start our series with the only facility (Stocamine, France) that was operated outside Germany and had to be permanently closed after a fire in 2002. The second article will deal with the mines in Kochendorf and Heilbronn (Baden-Württemberg, Germany). Further contributions concerning underground landfills and backfill mines in Germany will follow. In this way, we hope to provide a first overview of the history of the disposal of hazardous and radioactive waste in the geological underground and to give comparisons on the long-term risks of these strategies. Our compilations are intended to provide a basis for an in-depth discussion in science and society on the meaning of the strategies pursued to date and on the quality of the implementation of underground disposal.
However, it is questionable whether this is sufficient to draw the long-awaited lessons from the past practice of these disposal methods. After all, the low-cost disposal of industrial waste is supported by the markets, the economy and thus also by the authorities, both in the EU and in national administrations. It will take a lot to develop and implement correspondingly more expensive treatment measures to stop this ethically unsustainable transfer of toxic waste to future generations.