No individual covered by the provisions of this Part (rule) shall engage in, or require a person employed by him/her to engage in any prohibited activity unless precautionary action has been taken to protect against the danger from contact with a high-voltage line, either by de-energizing such high-voltage line and grounding it where necessary, or by other effective methods or devices which have been approved in advance for the particular case and for the particular location by the owner or persons in charge of such high-voltage lines.