In principle a decision by an authority may be contested first by filing an objection with the deciding agency. If the decision is upheld in the administrative review the claimant may bring an action against the decision before an administrative court.
To bring an action, claimants must be able to show that the intended act may violate their rights. This is the case, for example, if an approved project would impair a person’s property or health.
Additionally environmental and nature conservation law allows recognized environmental associations to bring actions before administrative courts without their own rights being affected (called “Verbandsklage”). These special remedies for environmental associations have their legal basis in the Environmental Appeals Act (Umwelt-Rechtsbehelfsgesetz, UmwRG) und the Federal Nature Conservation Act (Bundesnaturschutzgesetz, BNatSchG) and in corresponding provisions under the law of the German Länder. Before bringing an action associations must be recognized as environmental or nature conservation associations. You can find information on the requirements for recognition and the competent authority on the website Recognition of environmental and nature conservation associations.