Michigan Compiled Laws, Chapter 247. Highways § 247.184a

Sec. 14a. (1) A person shall not enter a manhole being constructed or being used for repairs to underground utilities or remain inside of the opening unless a person is providing alert surveillance, except that a new manhole under construction is exempted if adequate steps are taken to insure safe working conditions.

(2) A person, firm, or corporation authorized or permitted to construct or repair underground facilities by access through a manhole shall provide alert surveillance until the manhole cover is in place and no person remains in the underground facility. The second employee shall be trained in safety and first aid practices and shall be responsible for alert surveillance of the occupied manhole to afford immediate action in emergencies. The second employee could also perform other duties either above grade or in the manhole provided they did not interfere with the employees surveillance duties. This section does not preclude an employee trained in safety practices, in the absence of a second employee, from entering a manhole for a brief period of time not in excess of 20 minutes for purposes such as inspections, housekeeping, taking readings, or similar work, provided adequate steps have been taken to insure safe working conditions.