I do not see a check valve so there must be a foot valve at the bottom of the 1.5" pipe down in the well. If you cut the pipe and drop a string, you will only find out how deep it is to the check valve. I don't know what is under that concrete. I guess it could be a point well but, it is PVC pipe and would have to have been washed in. Wouldn't surprise me if the well is 4" pipe with 1.5" drop pipe for the pump, and just concreted instead of using a well seal.