The yardstick for contaminated-site remediation is hazard prevention. And because the principle of proportionality also needs to be observed in such cases, the officially imposed measures and the consequences thereof for the responsible party need to be reasonable relative to the hazard being averted. To this end, the measures that are carried out should be those most suitable (i.e. necessary) when it comes to achieving the desired outcome that would be achieved via a so called moderate measure and that at the same time entails a reasonable cost-benefit ratio.