Attractive Nuisance doctrine is really all that's needed. It's the same with PWR nuke plants; the "what happens when it goes wrong" is so bad as to imply easement upon all it's neighbors. The practical cost to really doing it is to be far, far away from others.
Los Angeles city council will hear a proposal on Tuesday to exempt union members from a $15 an hour minimum wage that the unions themselves have spent years fighting for.