S.D. Codified Laws § 62-7-12.2

In any contested case arising under the provisions of Title 62, any party, in person or by counsel, may informally request the hearing examiner who, in the ordinary course, would hear the contested case, to disqualify himself or herself. The requesting party may, but is not obligated to, state reasons for the request. The informal request may be by letter, by oral communication, or by motion not later than twenty days after notice of the appointment of the hearing examiner to the case. The opposing parties shall be apprised of the request, but may not contest the request. The director of the division shall grant the request and forthwith provide for the appointment of another hearing examiner. Neither party may request disqualification more than once on any case.