This topic includes the site operation during the decommissioning of the pilot site Ketzin. As field campaigns a back-production test of CO₂ and the injection of brine are planned. With these field experiments, the physicochemical changes of the CO₂ due to storage will be studied and the natural back-flow of the fluid into the storage formation after the end of the injection will be simulated. Further activities focus on the scientifically accompanied and monitored well abandonment and the decommissioning of the site. At one observation well (Ktzi 202) a stepwise abandonment will be conducted: The lower part of the well was already abandoned at the end of 2013 and has been monitored. In July 2015, the abandonment of the upper well was successfully completed. Thereafter, it is intended to abandon the four other research wells at the Ketzin pilot site.

The monitoring of the planned field campaigns and the post-closure phase are part of the second topic. With seismic measurements the CO₂ migration in the underground will be further monitored. Geoelectrical methods will be used to also monitor the planned injection of brine. In addition, the naturally occurring CO₂ fluxes from the soil will further be monitored. For these gas-chemical investigations mobile and fixed stations directly on the Ketzin pilot site and in its environment are used.

The third topic includes the integration of the huge Ketzin data set into a project database. In this long-term archive, raw data and results obtained are maintained. Extensive modeling of short-to long-term reservoir behavior were already carried out in previous projects. Based on new measurements, regular revisions of the geological Ketzin model were made. In this topic further model updates will be made​​, and simulations will be performed for the planned field campaigns.