Insulating water line from well to house
We are in the process of trying to buy a finished cabin in the wilds of Northern NH. Tha cabin sits on a slab, has a beautiful mt. view, 100 amp electric service and an artesian well. The mountain views are great as the house sits on a ledge.
My concern is the water line feeding the house from the artesian well. They had drilled down only 4 feet when they hit ledge. My question is assuming I only have 4 feet of soil to work with to protect the water feed from the cold temps of Northern NH winters, how should I best insulate this pipe to prevent freezing?
What would be some of the ways I can insulate the pipe without jackhammering through the rock?
Would the heating tape/strips ( essentially Romex wire) be the way to go?
Would inside the pipe heat tape be a viable solution or should be dig up the line (about 75′ from the well head to the house) pack the trench with insulation and wrap heat on the pipe externally and then cover it up?
Rigid insulation better than fiber glass?
Any other ideas? I could use some suggestions . Thanks in advance for all your help.