We were literally super close to signing the contract and entering into a sales agreement when we decided to hold off. This was after we received the disclaimer about not planting any fruit trees or any plants that have deep roots.
The chances of these roots tapping into that plume is unlikely however we did decide to pass on Augusta due to several other reasons.
However, the thought of the plume rising to the surface was scary enough to help us decide to hold off. Our dog eats everything on the ground...Again, very unlikely but we love our dog, errr "dinner".
If you want the disclaimer, all you have to do is ask the sales office for it however it is real and not an internet myth.