Maryland Code, Public Utilities § 18-107

(1) the general manager, secretary, treasurer, and chief engineer;

(2) the head of a department;

(4) a part time, temporary, or contract employee.

(1) appoint or promote a merit system employee to the position of general manager, department head, or inspector general or designate a merit system employee as the general manager, department head, or inspector general on an acting basis;

(2) retain the employee in the merit system in the position or grade from which the employee was appointed or promoted; and

(3) continue to exclude the positions of general manager, department head, and inspector general from the merit system.