Waste that is unsuitable for reuse, that cannot be incinerated and that is not excluded by law from being dumped, is deposited in one of our landfills. It is the character of the waste that determines if and how it can be dumped.

The waste is divided into different hazard classes, from C1 to C4, with C1 being the highest hazard class and C4 the lowest. Twence has landfill compartments that meet the criteria for the containment of C2, C3 and C4 waste.

Hazardous waste containment (C2)

Until 2003, residues from the waste-to-energy incineration plant that were unsuitable for reuse were dumped in the so-called C2 landfill compartment. As leftovers from the plant’s flue-gas purification process, those residues generally constitute three to four percent of the original amount of waste received. To ensure the safe storage of those residues, the separate C2 landfill compartment was given extra insulation, and the residues themselves were well packed in so-called big bags before being deposited there. Now the C2 landfill is no longer in use and has been provided with a final cover layer. Since early 2003, such residues are being usefully applied as filling for empty mineshafts in German salt and coalmines.

Hazardous waste containment (C3)

The C3 landfill is suited for the disposal of moderately leaching solid inorganic hazardous waste. This definitive form of final processing is used for a number of categories of waste streams such as galvanic filter cake, jet dust, friable asbestos and salts.

Non-hazardous waste (C4)

This class can include waste from drains, cesspools, sewers, ponds and waterways as well as sedimentation, waste material that contains asbestos, soil containing asbestos and soil that cannot be cleaned.