In the event of unusual or emergency circumstances or following the hiring of new employees, temporary certificates may be issued to an operator until a time when the operator can be examined and certified. Within two weeks after employment of such an operator, the department must be notified in writing and information shall be provided, including the operator's name, background, experience, training, education, and references. Thereafter, the operator may be issued a temporary certificate which shall remain valid only for that time required for the next routine examination and evaluation.