GSES GmbH has to comply with the mining authority's backfilling requirement in order to secure endangered mine workings. A survey has shown that this filling is essential, mainly in order to reduce the risk of rock burst and diminish surface subsidence in those parts of the town that have been undermined, and adjacent roads.

Not only rock salt but also non-mining mineral wastes are used as packing material. The company's efforts to offer ecologically and economically balanced disposal services are exemplified by complex approval procedures it has gone through to prove the suitability of individual waste substances as filling material, obtaining approval for the above ground treatment plants under the requirements of the BImSchG (Federal Immission Protection Law) including a UVP (Environmental Compatibility Assessment), proving the long-term safety of the mining fields for storage of waste, and obtaining recognition of the essential packing measures as recycling within the meaning of KrW-/ AbfG (Recycling Economy and Waste Law).

Underground packing is an attractive recycling option, particularly for dusty wastes produced by thermal processes (such as garbage incineration, metallurgy and the glass industry) and for filter cakes produced by, for example, the treatment of metal surfaces and wastewater. This also applies to bulk materials from the clearing of hazardous waste sites and furnace chippings from smelting processes.