... effective methods or devices which have been approved in advance . . . . [ N.J.S.A. 34:6-47.2.] In addition, N.J.S.A. 34:6-47.5 ... responsible person who is required to take "precautionary action" under N.J.S.A. 34:6-47.2, must promptly notify "the owner or person in charge of ... close proximity to ACE's high-voltage power lines. Under N.J.S.A. 34:6-47.2, Duall could not permit its employees to perform any activity ...