The „Brown Bear Judgment“ by the ECJ and the decision on the air protection plan of the city of Darmstadt by the Federal Administrative Court have introduced important changes to procedural legal protection in environmental law matters. The ECJ’s Altrip decision left open whether for this purpose an alleged violation of procedural law would also need to have an impact on the substantive outcome of a case in the sense of a violation of substantive law. Conceptually, public