6.12. One objective of the monitoring programme for the period after closure, if this is part of the post-closure safety case, is to detect radioactive material and/or other toxic material in the environment that could be attributable to the disposal facility. However, this is only one part of the monitoring programme after closure, and its importance differs for different types of disposal facility. The extent, duration and importance of post-closure monitoring vary among the different types of disposal facilities and the type of waste disposed of. Institutional controls applied after closure of the disposal facility may be of an active or passive nature. Examples of active institutional controls are the monitoring of radionuclide concentrations in the environment and the monitoring of the performance and integrity of barriers, which is important in particular for near surface disposal facilities.