As of the 1980s, the European Court of Justice and infringement proceedings have become important instruments for the European Commission to encourage Member States to comply with European environmental law. This article examines how such compliance is achieved, through a case study of the infringement proceedings against France relating to the contamination of several rivers containing nitrates in the 1990s–2000s. It shows that compliance with European environmental law can be analysed as the result of a process during which the meaning of European norms and the modes of compliance with said norms are debated. This, being a lengthy process, gives actors the opportunity to play with time, particularly with a view to obtaining new extensions and renegotiating the interpretation and conditions of the application of norms. This may result in a gradual dilution of the rule of law, in as much as its modes of application can be made considerably more flexible.