That makes sense, but then why not then advise the pet owner to flush the cat's poop down the toilet? Seems simpler than having a special container and a return trip to the vet.
Cat litter + indoor plumbing = not a good time.
I did think it seemed kind of silly though. Like the state is really gonna hunt down whoever threw away radioactive cat poop.
The whole thing was more about 9/11 / terrorism than environmental damage.