Due to its swelling volume, bentonite is ideally suited for backfilling boreholes. At every new construction site, exploratory drillings by the ordnance disposal service must be carried out and holes checked for possible dangers. Even with other boreholes, such as for water, gas, oil etc., regardless of whether they are dry or flushing boreholes, these must be closed again afterwards. In order to be able to restore the groundwater retaining sediments and to prevent the water from flowing away, they are filled with bentonite and compacted. Depending on the need and application, this is done with the help of bentonite pellets or bentonite granules as well as suspensions containing bentonite.