Originally the pool builder had told us they were going to put the fiberglass and the deck concrete into the hole. Sounded like it was done that way quite commonly. The excavator said "no" the day of excavation. He didn't feel that was the way to go with the new pool going in a few feet away. He asked the pool builder to find out where he could haul the concrete deck material. The builder just looked blank, I got on the phone with the guy at the local dump errrr, environmental controlled refuse station, he said one of the local construction companies would take concrete for free in any size to use for fill. The excavator hauled the concrete to the construction company and took the fiberglass away. I have no idea where it went.