In the case of hearings pursuant to RCW 70A.10.160 the department shall, and in other cases may, cause a record of the proceedings to be taken and filed with the department, together with its findings and conclusions. For any hearing, the director of the department or a representative designated by him or her is authorized to administer oaths and affirmations, examine witnesses, and issue, in the name of the department, notice of the hearing or subpoenas requiring any person to appear and testify, or to appear and produce documents, or both, at any designated place.