(1) Purpose. The purpose of any hearing is for the parties to present oral argument based on the record as presented in their briefs and exhibits and for the board to ask questions necessary for a thorough understanding of the issues for decision.

(2) Presiding officer. All hearings shall be conducted by a presiding officer who shall conduct the hearing in an orderly manner and rule on all procedural matters, objections, and motions.

(3) Order of presentation. The presiding officer shall determine the proper order of presentation and the time allotted for presentation. Time allotted to petitioners and respondents will be roughly equal, with parties responsible for dividing their time with supporting intervenors, if any.

(4) Illustrative exhibits. Any proposed illustrative exhibit shall be circulated to the parties at least four days prior to the hearing. Paper copies of any illustrative exhibit, in pleading size, shall be brought to the hearing for the benefit of the board and the parties.

(5) Supplemental evidence submitted at hearing. In exceptional circumstance the board may allow the submission of supplemental evidence at a hearing in response to board questions, upon a showing that the supplemental evidence is necessary or of substantial assistance to the board. If supplemental evidence is thereby introduced, the opposing party shall have the opportunity to respond. The board may require the parties to submit post-hearing briefing or documents detailing the supplemental evidence, and the opposing party's rebuttal to the supplemental evidence.