THE CHALLENGE: Contamination investigations on the premises of a former gasworks showed considerable contaminations with gasworks-specific pollutants, especially with polycyclic aromatic hydrocarbons. The contaminations in the soil were in some areas up to 8 metres deep and were therefore located in the groundwater area. When investigating the site's downstream area, heavily contaminated groundwater was detected. The proximity to Lake Constance was to be taken into consideration when evaluating the dangers posed by the contaminated area.

THE APPROACH: ARCADIS cleaned up the contaminated site by excavating the contaminated soil. An excavation grid was applied. The excavated material was separated on site, which was also used for intermediate storing. After an external chemical expert had evaluated and analyzed samples, the site supervisor released the material for transportation. Slightly contaminated material was disposed of on a landfill, whereas highly contaminated material received heat treatment.

THE RESULT: A city center freed of the negative consequenses of its early industrial  past and an end to the threat of contamination to the larger area, inlcuding Lake Constance.
DE00298