The director of each department may, from time to time, designate and deputize one of the assistant directors of his or her department to act as the chief assistant director, who shall have charge and general supervision of the department in the absence or disability of the director, and who, in case a vacancy occurs in the office of director, shall continue in charge of the department until a director is appointed and qualified, or the governor appoints an acting director.
RCW 43.17.040