A federal appeals court will decide whether Colorado has the authority to set a deadline for destroying chemical weapons stored at an Army facility outside Pueblo.
Attorneys for the state and the Army made their case before judges at the 10th Circuit Court of Appeals in Denver Wednesday.
Colorado says the Army needs to come up with a compliance schedule to meet the 2017 deadline set by Congress to dispose of mustard agent stored at the Pueblo Chemical Depot.
The Army says Colorado doesn't have authority to force a deadline. It says the munitions will be destroyed by 2021.
A federal judge previously ruled that federal law limits the state's authority to set timelines and deadlines.
It's not known when the appeals court will issue a ruling.