Yes, Texas law says you have to call any time any kind of excavation is performed.
It will not cut through rocks, but if rocks are mixed in with soil it just slows things down.
No, it becomes a slurry and would never dry. Different dirt needs to be put back in the hole.
Whoever requested the excavation can fill the hole or we can fill it at an extra charge.
Of course, the size of the hole determines most of that. But soil conditions play a big part. Clean black soil is quickest, rocks and roots slow the process.
We can work our way through a lot of boring situations.