That understanding was thoroughly corrected by the Supreme Court in 1991 in the so-called Rockwool case:
In 1962 the enterprise Rockwool, which manufactures insulation material, purchased a neighbouring site with the intention of subsequent expansion. The enterprise that previously owned the site had left in place a couple of oil storage tanks which were inspected at the time of purchase and found to be empty. In 1987, Rockwool started to construct an administration building. During excavation part of the site was discovered to be contaminated with oil. Citing the regulations concerning oil storage tanks, the Municipality instructed Rockwool to clean up the pollution. The injunction was appealed to the Danish EPA, but the latter dismissed the appeal. The enterprise elected to remediate the site, but simultaneously brought a case against the two environmental authorities. The clean-up costs amounted to DKK 600,000.
The Supreme Court upheld Rockwool’s contention that the injunction had been unlawful and the expenses should be refunded. In its ruling the Court attached importance to the fact that the Environmental Protection Act does not provide the legal basis to depart from the normal liability rules pertaining under Danish law. Rockwool had not caused the contamination, and in fact did not even know that it had purchased a contaminated site.
Thereafter the environmental authorities have had to instead focus their attention on the possibilities for ordering the polluter to clean up.
As discussed in Section 8.4, remediation of contamination caused by leaky subterranean household heating oil storage tanks is most often undertaken at the expense of the insurance companies. In fact, though, it is unclear whether their responsibilities actually cover such cases.
Other than that, however, the authorities have problems in finding a solution to cases. The Environmental Protection Act is formulated with a view to regulating future pollution. It is difficult to use on past pollution, and the local authorities have often been stopped by legal difficulties.
From the technical point of view the correct approach is to first determine the extent and magnitude of the pollution and thereafter undertake remediation, e.g. removal of the soil, abstraction and treatment of the groundwater, etc.
However, the legal problems start as soon as the authorities order the owner to determine the extent and magnitude of the pollution. It is unclear how far the authorities can go in demanding investigations.
In a few cases the local authorities have elected to undertake site remediation themselves, and then take the polluter to court. In these cases the court bases its judgement quite simply on whether the polluter has acted negligently. If he has, then he must pay compensation for the investigation and clean-up costs.
Progress with respect to remediation of "newer" contaminated
sites has generally been severely hindered by the above mentioned problems. Clean-up after
pollution caused by leaky subterranean household heating oil storage tanks is undertaken
routinely thanks to the insurance companies. Clean-up of other sites almost only takes
place if the enterprise responsible unconditionally accepts to clean up. If that is not
the case, then the environmental authority, i.e. the Municipality or the County, has to
undertake the clean-up itself, something which it is reluctant to do because of resultant
budget problems. The Counties and Municipalities have now become so frustrated over the
difficulties these cases present that they are trying to get landowner liability
introduced, i.e. the possibility to issue injunctions forcing a landowner to remediate the
land irrespective of whether or not he himself is the polluter.