The idea of exploiting shale hydrocarbons has generated vivid and intense controversy in the European space, both at central and civil society levels. These controversies are due, on one hand, to the issue of the injection of hazardous chemicals during the exploitation process and, on the other hand, to the imbalance between the economic benefits of exploiting these hydrocarbons (the specific production of hydrocarbons being very low) and the environmental risks and challenges which under these conditions are not compensated. Given the fact that in the extraction process important land plots are diverted from other uses (e.g. agriculture) and the high possibility (close to certainty) of contamination of geological substrates (including groundwater), while the shale hydrocarbon deposits in Europe are too small to have a significant impact on the gas supply, we have considered that a simplified methodology for assessing the environmental risks associated with their exploitation is necessary. Among the possible risks, we mention: the discharge of fracturing fluid; the leakage of wastewater from ponds and pipes transporting fracturing fluid; the emissions of potentially explosive, greenhouse effect amplifying, carcinogenic and radioactive enhancing gases; changes in zonal seismicity etc. Considering the relationship according to which the environmental risk caused by an undesired event is equal to the probability of producing that event multiplied by the vulnerability of the natural and anthropic environment, at the time of that event, the proposed methodology is based on quantitative and qualitative data characterizing the American experience. We have started from this data because in Europe (in regions such as: Poland, France, Germany and Scandinavian peninsula) the extraction of shale hydrocarbons is at the beginning, while the United States has an experience in the field of over 45 years, with more than 50 thousands operating wells.

environmental impact, shale hydrocarbons, risk assessment, land contamination

environmental engineering

Presentation: oral