Kernrechtsfrage
Whether the cantonal authority or BAZL was competent to issue the cost-allocation decision under Art. 32d(4) USG.
Extrahierter Entscheid
The authority that ordered and materially directed the remediation measures must also issue the cost-allocation decision; here that was the cantonal AWEL, not BAZL.
Extrahierte Begründung
Cost allocation is closely linked to the remediation measures under Art. 32c USG. Federal competence under Art. 41(2) USG exists only where the remediation is carried out in direct connection with the execution of another federal law. The remediation here was led by AWEL independently of the aviation-planning procedure.