I think the storage was one of convenience. Ship was at the docks, so store it at the docks. Who would have thought it would have taken 6 years? The next problem is this 2750 tons of material. You're talking around 70 semi loads to carry it all off. This has to be funded by someone, who?
I mean, at the bare minumum someone must have been willing to take this stuff off the states hands at least for free, right? A Google search says 500$ a ton for it
Very few people need explosive grade ammonium nitrate in this quantity and also prefer a source that has no provenance, and pay some fraction of 1.3 Million list price over their established supply chain.