"Emergency" means any situation arising from a sudden and reasonably unforeseeable event beyond the control of the owner or operator, including an act of God, that requires immediate corrective action to restore normal operation, and that causes the source to exceed an emission limitation contained in the operating permit which is based on a specific type of technology. The term does not include the failure to comply with emission limitations because of the improper design of the source, the lack of preventative maintenance, the careless or improper operation of the source, or any error by the operator.
Nev. Admin. Code § 445B.056
NRS 445B.210