S.D. Codified Laws § 10-50-51

The court may grant equitable relief and may order the treasurer to pay the amount of the relief, with interest at the rate of eighteen percent per year to the aggrieved taxpayer. If the appeal was taken without probable cause, the court may double or triple costs as the case may demand. On all appeals which are denied, costs may be taxed against the appellant at the discretion of the court, but no costs may be taxed against the state.