99. In an underground mine, no new ventilation installation or change in existing installation shall be undertaken unless plans and specifications, including, in particular, illustrations of the direction and volume of air displacement, location of fans, fire doors, doors and bulkheads used to control air circulation, have been obtained from an engineer. The plans shall be:(1) updated not later than 1 February of each year so that the plans indicate the state of the ventilation at 31 December of the preceding year;
(2) kept on the site of the mine and be available at all times.
A copy of the plans and specifications shall be sent to the Commission where it so requests.