Characterizing groundwater flow in a former uranium mine (Berthol`ene, France): Present status and future considerations

Study region: Berthol`ene is a former uranium mine in Aveyron, where tailings and waste rocks are stored in a natural valley. This results in acid mine drainage (AMD) at the outlet of the tailings storage facility (TSF), where there is a dedicated water treatment plant. Study focus: A detailed data analysis was conducted using data from 13 piezometers and from long-term monitoring of the local climate. A 3D model was developed using MODFLOW to understand groundwater flows at the catchment scale and identify flow paths from the contamination sources within the TSF. Previous geochemical modeling of TSFs had indicated that AMD was expected to occur for 50-100 years, therefore the site must be managed with a long-term view. As climate change may affect not only the recharge but also the frequency and intensity of extreme events, its impact on water balance and water levels at the site has to be studied for the next 100 years. New Hydrological Insights for the Region: Data analysis provides information about the unsaturated conditions within the tailings. Then water balance calculations at the TSF outlet validate the contribution of two different water zones. Modeling using the recharge estimation supports the current functioning of the catchment. The impact study of extreme events shows that the water table should not permanently reach the tailings over the next century.

Automated summary

This study focused on a former uranium mine in Aveyron and conducted a detailed data analysis, as well as developed a 3D model to understand groundwater flows and contamination sources. The results indicated that acid mine drainage may occur in the next 50-100 years and long-term management is necessary. Additionally, the impact of climate change on water balance and water levels needs to be studied for the next century.