1.1.1 Purposes of monitoring

The principal purposes for monitoring of storage complexes and their surroundings are:

  • HSE monitoring: Health, safety and environmental (HSE) provisions, which are in the focus of Annex II of the European CCS Directive, are the main reason for storage monitoring, especially with respect to human safety. It includes standard monitoring for normal operations, according to permitted conditions as well as contingency monitoring in the case of unexpected events.
  • ETS monitoring: Quantification of emissions from storage sites according to the European Emission Trading System (ETS; as defined in the Directive 2003/87/EC, the EU ETS Directive), is required in order to assure that CO2 storage is compatible with the overall aim of providing a market-based mechanism for emission reduction.
  • Operational monitoring: Providing technical data for injection management and site operation. Monitoring the migration of the CO2 plume within the storage complex is needed for efficient storage operation. This may be of economic interest to the operator. It may be required by regulators also who care for an efficient utilisation of limited underground storage space.
  • Informational monitoring: Satisfying the public interest on environmental information, especially in inhabited areas and in the case of deviations from the predicted storage behaviour. Though some of these data may neither be required by the regulators, nor needed for storage operation, providing such data may be critical for the local acceptance of on-shore storage sites in particular.