[Hoot Gibson]

Do you know the answer to my question on post 16?

I have no idea how the "island" was built and whether the description of it being constructed of gravels is accurate - so no, I would have venture a guess as to whether it is possible that the island would shift and rupture the well casing. However, the well casings are pretty substantial and I seriously doubt that the island consists of a pile of loose gravels as the author implies. It was more likely built in thin lifts and compacted with a bulldozer or roller as it was constructed.