S.D. Codified Laws § 34A-2-94
Any records, reports, or information obtained under this chapter shall, in the case of effluent data, be related to any applicable effluent limitations, pretreatment, or new source performance standards, and shall be available to the public. However, upon a showing satisfactory to the secretary by any person that records, information, or particular part thereof (other than effluent data, permit applications, and permits) to which the secretary has access under this chapter, if made public, would divulge methods or processes entitled to protection as trade secrets of such person, the secretary shall consider the record, report, or information, or particular portion of the record, report, or information, confidential, except that such record, report, or information may be disclosed to other officers, employees, or authorized representatives of the state or federal government concerned with carrying out this chapter, or when relevant, in any proceeding under this chapter.
SDCL 34A-2-94