Abstract The Geological Survey of Denmark and Greenland (GEUS) has a long history and over the years there has been a strong focus on traditional survey work such as geological mapping, research and advice to authorities on questions related to geological and natural resources. Many of the services provided are continuing in the years to come but modern, complex society engenders new questions, where decisions must be based on the best available knowledge, and geological surveys are key players to provide this knowledge to governments. In the new millennium, GEUS has entered into a number of long-term environmental monitoring programmes and several political sensitive projects. Key examples described include groundwater monitoring, assessment of the risk of pesticide leaching to the groundwater, disposal of low-radioactive waste, Carbon Capture and Storage the Continental Shelf Project of the Kingdom of Denmark, monitoring of the Greenland Inland Ice, and other activities on the ice shield. It is expected that GEUS will be involved in even more such studies in the coming years and that the modernization of classical studies will continue. The revised strategy of GEUS to be launched in 2020 will be focused on the institutions input to meet the United Nations sustainable goals.

Abstract In a deep geological repository (DGR) for the long-term containment of radioactive waste, gases could be generated through a number of processes. If gas production exceeds the containment capacity of the engineered barriers or host rock, these gases could migrate through these barriers and potentially expose people and the environment to radioactivity. Expansive soils, such as bentonite-based materials, are currently the preferred choice of seal materials. Understanding the long-term performance of these seals as barriers against gas migration is an important component in the design and long-term safety assessment of a DGR. This study proposes a hydro-mechanical linear poro-elastic visco-capillary mathematical model for advective-diffusive controlled two-phase flow through a low-permeability expansive soil. It is based on the theoretical framework of poromechanics, incorporates Darcy’s Law for both the porewater and poregas, and a modified Bishop’s effective stress principle. Using the finite element method (FEM), the model was used to numerically simulate 1D flow through a low-permeability expansive soil. The results were verified against experimental results found in the current literature. Parametric studies were performed to determine the influence on the flow behaviour. Based on the results, the mathematical model looks promising and will be improved to model flow through preferential pathways.