Antarctica would make a perfect waste storage site.
Its a frozen uninhabited slag heap. Large areas of the continent are bone dry and would make a perfect disposal sight. Its isolation would make it very easy to guard against any terrorist threats. The UN could even be put in charge of running the place. A few hundred blue helmets could do the job.
A small port could be built on the coast with a rail line running inland to the storage facility, and every Spring waste from around the world could be brought there for permanent storage.