Even the most positive minded public official can see the liability and PR problems with that. Providing beach sand to local cities was one of the ways in which the Navy enlisted public support for its nuclear carrier homeporting plan, and finding ordinance in the dredged material should come as no surprise to the Navy. The Navy certainly has the expertise in ordinance management somewhere. I cannot believe that the Navy does not have the capability to make good on its promise to deliver the sand. Beach movement is natural.
Beaches are constantly in motion.
The beach you saw last summer is not the same beach that's there today. Billions and billions of grains of sands are removed and added incessantly. While big storm events can remove entire beaches, in a natural coastline, the sand comes back. But the key here is removed and deposited, removed and deposited. But beach erosion and persistent disappearance is mostly a manmade problem.