Section 75.389 - Mining into inaccessible areas(a)(1) The operator shall develop and follow a plan for mining into areas penetrated by boreholes drilled under § 75.388 .(2) Mining shall not resume into any area penetrated by boreholes until conditions in the penetrated area can be determined under § 75.388 and the plan for mining-through into the area has been approved by the district manager.(3) A copy of the procedures to be followed shall be posted near the site of the mining-through operations and the operator shall explain these procedures to all miners involved in the operations.(b) The procedures specified in the plan shall include- (1) The method of ventilation, ventilation controls, and the air quantities and velocities in the affected working section and working place;(2) Dewatering procedures to be used if a penetrated area contains a water accumulation; and(3) The procedures and precautions to be followed during mining-through operations.(c) Except for routine mining-through operations that are part of a retreat section ventilation system approved in accordance with § 75.371(f) and (x) , the following provisions shall apply: (1) Before and during mining-through operations, a certified person shall perform air quality tests at intervals and at locations necessary to protect the safety of the miners.(2) During mining-through operations, only persons involved in these operations shall be permitted in the mine; and(3) After mining-through, a certified person shall determine that the affected areas are safe before any persons enter the underground areas of the mine.