The cavities created are filled with highly environmentally compatible materials of mineral origin that have been authorised and approved by the mining authorities.
The use of waste material as minefill is subject to stringent regulations. The requirements for the materials are governed by the Ordinance on Underground Waste Fills. Further requirements concerning environmental protection, health and work safety, and quality assurance are listed in the Technical Regulations.
The materials are shipped via the Mosel river in an environmentally friendly manner or transported in bulk, packaged in Big Bags, by lorry.