This thesis investigates whether a property owner’s obligation to clean-up a contaminated site is constitutionally valid, the liability being limited by the decision of the Federal High Court from 16.02.2000, when the degree of contamination was unknown at the point of purchase. Possible remedial measures are described and classified according to the dogmatic structure of Article 14 of the German Constitution. The justification for such measures is discussed with the result that the remediation first and foremost serves to repair the environmental damage. Hazard prevention plays a secondary role. This finding, together with the comparison of relevant national and European legislation, shows that the property owner’s obligation should be reconsidered. A critical analysis of the aforementioned decision of the Federal Constitutional Court can, therefore, not be considered to be the final word in this matter as this decision does not guarantee proper constitutional implementation. In conclusion, prospective reform requirements and possible legal solutions are described.