Underground CO2 storage facilities are designed to contain CO2 permanently and the expected performance scenario is that no CO2 leakage from the storage complex will occur. However, it is necessary to assess the possible environmental impacts of CO2 leakage in the unlikely event that a storage system evolves differently from the design aim. The RISCS project is being undertaken under the European Union's 7th Framework Programme to research these potential impacts. To help focus RISCS research and aid communication of the results, a set of reference terrestrial and marine European receptor environments and associated impact scenario descriptions were defined systematically by evidence-based expert elicitation.
