On Fri, 12 May 2017 17:44:02 GMT, Michael
m wrote:

In a stone and clay crawl space, digging down I hit concrete along the wall?
How far from wall should I go through it so as not to risk the foundation
footing? I'll have to rent some kind of jackhammer to get through it.

Try another hole a foot or so away from the wall. The footer should be
~18" wide. You should be able to miss it if you get a foot or two away
from the wall.