74:51:01:25.01Application of

criteria to protect attainable beneficial use. If the secretary determines that a water body is supporting a higher existing beneficial use than is currently designated for that water body, the secretary may apply the criteria found in §§ 74:51:01:31, 74:51:01:32, and 74:51:01:44 to 74:51:01:55, inclusive, that are necessary to protect that higher attainable beneficial use. In any case, for all waters that remain Class 9 following analysis or which are designated as Class 9, the secretary may apply the provisions of § 74:51:01:55 in controlling the discharge or presence of pollutants which could reasonably be expected to interfere with the uses included in Class 9 and as necessary to support those uses.

Source: 25 SDR 98, effective January 27, 1999.