Ohio Rev. Code § 1563.41: Sealing off abandoned workings.

The operator of a mine, before sealing off any abandoned workings, shall obtain the approval of the deputy mine inspector and the chief of the division of mineral resources management. The seals used in sealing off such workings, when approved by the chief, shall be constructed of not less than eighteen-inch concrete or masonry bulkheads effectively anchored to the ceiling, ribs, and floor, except where seals are used to seal abandoned individual panel or room entries, they shall be constructed of concrete or masonry bulkheads not less than six inches in thickness effectively anchored to the ceiling, ribs, and floor in a manner approved by the deputy mine inspector and the chief. All seals are to be bled or drained of gas in a manner approved by the deputy mine inspector and the chief.

No operator of a mine shall refuse or neglect to comply with this section.