Ongerechtvaardige verrijking: een systematische analyse van het begrip ongerechtvaardigheid, toegepast op kostenverhaal bij bodemsanering

The subject of unjust enrichment has attracted many authors in The Netherlands. Specifically the question whether an enrichment should be considered unjust has given rise to a variety of opinions. However, this scholarly attention has not led to a widely accepted and practical understanding of unjust enrichment in Dutch law. It remains unclear what criteria should be used in a specific case. Any approach to unjust enrichment should be an integral part of Dutch civil law. In my opinion the best way to achieve this is by studying other types of legal actions in Dutch civil law. A comparison with tort has been chosen for this study. This comparison is based on three hypotheses. The first hypothesis deals with the fact that in my view unjust enrichment and tort law are part of a bigger whole: The necessity to rectify an unjustified situation. Whereas unjust enrichment is used to remedy those situations where an enrichment has come to exist that can not remain with the enriched party, tort law is concerned with correction of situations where damage has occurred. In other words: unjust enrichment law deals with the ‘plus’ and tort law deals with the ‘minus’. The advantage of placing unjust enrichment into a larger perspective that also contains tort, is that developments in the field of tort can be applied to better understand unjust enrichment. Of course this can only be true if developments in tort law have come so far that it is understood when the occurrence of damage should be considered tortuous. This leads to the second hypothesis: The development of tort has reached the point where the grounds for tort in written and unwritten law have become clear. If this hypothesis is accepted, a third hypothesis can be formulated: If the first and second hypothesis are accepted, the grounds for liability and the way they are applied could be the same for tort and unjust enrichment. This third hypothesis forms the basis for the systematic approach to determine whether an enrichment is unjust. According to this hypothesis the way it is decided if damage has occurred tortuously is similar to the way in which an enrichment is judged to be unjust. This means that to understand unjust enrichment, one has to understand tort. An analysis of tort in The Netherlands is therefore needed