S.D. Codified Laws § 3-13-93

If, due to an error, a participant defers more than the permissible amount, the third-party administrator may correct the error by returning the excess deferral to the participant. For any plan year in which a participant makes both pre-tax contributions and designated Roth contributions, any corrective distribution must be taken first from the participant's designated Roth contributions, and then, if required, from the pre-tax contributions. A participant may elect a different method of distribution.