The presiding officer may require parties and amici curiae to file written statements of position prior to the beginning of a hearing. The presiding officer may also require the parties to submit trial briefs.

(a) The hearing is directed to receiving factual evidence and expert opinion testimony related to the issues in the proceeding. Argument will not be received in evidence; rather it should be presented in statements, memoranda, or briefs, as determined by the presiding officer. Brief opening statements, which shall be limited to statement of the party's position and what he intends to prove, may be made at hearings.

(b) Hearings for the reception of evidence will be held only in cases where issues of fact must be resolved in order to determine whether the respondent has failed to comply with one or more applicable requirements of part 80 of this title. In any case where it appears from the respondent's answer to the notice of hearing or opportunity for hearing, from his failure timely to answer, or from his admissions or stipulations in the record, that there are no matters of material fact in dispute, the reviewing authority or presiding officer may enter an order so finding, vacating the hearing date if one has been set, and fixing the time for filing briefs under § 81.101. Thereafter the proceedings shall go to conclusion in accordance with subpart J of this part. The presiding officer may allow an appeal from such order in accordance with § 81.86.

Testimony shall be given orally under oath or affirmation by witnesses at the hearing; but the presiding officer, in his discretion, may require or permit that the direct testimony of any witness be prepared in writing and served on all parties in advance of the hearing. Such testimony may be adopted by the witness at the hearing, and filed as part of the record thereof. Unless authorized by the presiding officer, witnesses will not be permitted to read prepared testimony into the record. Except as provided in §§ 81.75 and 81.76, witnesses shall be available at the hearing for cross-examination.

Proposed exhibits shall be exchanged at the prehearing conference, or otherwise prior to the hearing if the presiding officer so requires. Proposed exhibits not so exchanged may be denied admission as evidence. The authenticity of all proposed exhibits exchanged prior to hearing will be deemed admitted unless written objection thereto is filed prior to the hearing or unless good cause is shown at the hearing for failure to file such written objection.

An affidavit is; not inadmissible as such. Unless the presiding officer fixes other time periods affidavits shall be filed and served on the parties not later than 15 days prior to the hearing; and not less than 7 days prior to hearing a party may file and serve written objection to any affidavit on the ground that he believes it necessary to test the truth of assertions therein at hearing. In such event the assertions objected to will not be received in evidence unless the affiant is made available for cross-examination, or the presiding officer determines that cross-examination is not necessary for the full and true disclosure of facts referred to in such assertions. Notwithstanding any objection, however, affidavits may be considered in the case of any respondent who waives a hearing.

Upon such terms as may be just, for the convenience of the parties or of the Department, the presiding officer may authorize or direct the testimony of any witness to be taken by deposition.

Not later than 15 days prior to the scheduled date of the hearing except for good cause shown, or prior to such earlier date as the presiding officer may order, any party may serve upon an opposing party a written request for the admission of the genuineness and authenticity of any relevant documents described in and exhibited with the request, or for the admission of the truth of any relevant matters of fact stated in the request. Each of the matters of which an admission is requested shall be deemed admitted, unless within a period designated in the request (not less than 10 days after service thereof, or within such further time as the presiding officer or the reviewing authority if no presiding officer has yet been designated may allow upon motion and notice) the party to whom the request is directed serves upon the requesting party a sworn statement either denying specifically the matters of which an admission is requested or setting forth in detail the reasons why he cannot truthfully either admit or deny such matters. Copies of requests for admission and answers thereto shall be served on all parties. Any admission made by a party to such request is only for the purposes of the pending proceeding, or any proceeding or action instituted for the enforcement of any order entered therein, and shall not constitute and admission by him for any other purpose or be used against him in any other proceeding or action.

Irrelevant, immaterial, unreliable, and unduly repetitious evidence will be excluded.

A witness may be cross-examined on any matter material to the proceeding without regard to the scope of his direct examination.

Letters expressing views or urging action and other unsponsored written material regarding matters in issue in a hearing will be placed in the correspondence section of the docket of the proceeding. These data are not deemed part of the evidence or record in the hearing.

Objections to evidence shall be timely and briefly state the ground relied upon.

Exceptions to rulings of the presiding officer are unnecessary. It is sufficient that a party, at the time the ruling of the presiding officer is sought, makes known the action which he desires the presiding officer to take, or his objection to an action taken, and his grounds therefor.

Where official notice is taken or is to be taken of a material fact not appearing in the evidence of record, any party, on timely request, shall be afforded an opportunity to show the contrary.

Whenever there is offered (in whole or in part) a public document, such as an official report, decision, opinion, or published scientific or economic statistical data issued by any of the executive departments (or their subdivisions), legislative agencies or committees, or administrative agencies of the Federal Government (including Government-owned corporations), or a similar document issued by a State or its agencies, and such document (or part thereof) has been shown by the offeror to be reasonably available to the public, such document need not be produced or marked for identification, but may be offered for official notice, as a public document item by specifying the document or relevant part thereof.

An offer of proof made in connection with an objection taken to any ruling of the presiding officer rejecting or excluding proffered oral testimony shall consist of a statement of the substance of the evidence which counsel contends would be adduced by such testimony; and, if the excluded evidence consists of evidence in documentary or written form or of reference to documents or records, a copy of such evidence shall be marked for identification and shall accompany the record as the offer of proof.

Rulings of the presiding officer may not be appealed to the reviewing authority prior to his consideration of the entire proceeding except with the consent of the presiding officer and where he certifies on the record or in writing that the allowance of an interlocutory appeal is clearly necessary to prevent exceptional delay, expense, or prejudice to any party, or substantial detriment to the public interest. If an appeal is allowed, any party may file a brief with the reviewing authority within such period as the presiding officer directs. No oral argument will be heard unless the reviewing authority directs otherwise. At any time prior to submission of the proceeding to it for decisions, the reviewing authority may direct the presiding officer to certify any question or the entire record to it for decision. Where the entire record is so certified, the presiding officer shall recommend a decision.