Section 159-13-001 - REQUIREMENT OF DESIGNATION AND TRAINING UST OPERATORS001.01 An owner or operator will designate Class A, Class B, and Class C operators for each underground storage tank system or facility that has underground storage tanks regulated by the State Fire Marshal, except for unstaffed facilities for which only Class A and B operators will be designated. A person may be designated for more than one Class of operator.159 Neb. Admin. Code, ch. 13, § 001