Abstract: The method of sealing a polluted area containing pollutants to prevent transport of the pollutants from the polluted area includes forming a sealing barrier layer around the polluted area underneath and/or next to it by feeding a liquid sealing material into the liquid permeable ground and fissures under and/or next to the polluted area or into the polluted area by a plurality of injection lances and/or pressure probes from above ground or from the surface of the polluted area. The liquid sealing material is a Montan wax emulsion or a mixture of the emulsion with earth and/or pollutants, the Montan wax emulsion is made from 10 to 20 parts by weight Montan wax, 3 to 5 parts by weight emulsifier, 100 parts by weight of water and from 0 to 10 by weight of a stabilizer.