When an agency is required by law to hold public hearings before adopting, amending or repealing a regulation and, otherwise, if an agency in its discretion determines to hold public hearings, in addition to giving opportunity for the submission of written materials, the following shall apply to the conduct of such hearings:
(1) The hearing shall be conducted either by the agency or by a subordinate designated by the agency for that purpose who shall be empowered in connection with such hearing to:
a. Issue subpoenas, in the agency's sole discretion, for witnesses or other evidence, on the agency's initiative or at the request of any person;
b. Administer oaths to witnesses; and
c. Exclude irrelevant, immaterial, insubstantial, cumulative, privileged matter and unduly repetitive proofs, rebuttals and cross-examination.
(2) A record from which a verbatim transcript can be prepared shall be made of all hearings. The expense of preparing any transcript shall be borne by the person requesting it. No part of the public hearing is exempt from this record requirement.
(3) If the hearing notice includes a specific length of time for the holding of the hearing, the hearing shall not adjourn prior to the end of that length of time.