All persons possessing certificates of qualification heretofore issued by the Department of Mines of this state, or by the Division of Mines and Minerals, or hereafter by the Office of Miners' Health, Safety and Training entitling them to act as mine foreman-fire bosses, or assistant mine foreman-fire bosses, are eligible to engage at any time as miners in the mines of this state. Supervisory and technically trained employees of the operator, whose work contributes only indirectly to mine operations, are not required to possess a miners' certificate.

Notwithstanding the provisions of this article, every person working as a surface miner in this state on or before July 1, 1974, shall, upon application to the director, be issued a certificate of competency and qualification.