More stringent SSC

More stringent SSC. More stringent SSC. A waterbody or segment is eligible for a more stringent SSC if the requestor demonstrates and the department determines that the statewide phosphorus criterion is not sufficiently protective of the waterbody’s designated uses. A more stringent SSC may be appropriate if a waterbody is in one of the following categories: (1) Biological metrics not attained. A more stringent SSC may be appropriate if a waterbody attains its statewide phosphorus criterion but does not attain one or more of its phosphorus response indicators or biological assessment thresholds. However, a more stringent SSC is not appropriate under this subsection if a biological assessment threshold or phosphorus response indicator is not attained due to factors other than phosphorus, and the department determines that phosphorus is not contributing to the nonattainment. (2) Biological metrics attained. A more stringent SSC may be appropriate even if a waterbody is below its statewide phosphorus criterion and it attains its phosphorus response indicators and biological assessment thresholds if it is demonstrated that a more stringent SSC than the statewide phosphorus criterion is necessary to maintain attainment of any of these indicators and the level necessary can be demonstrated through modeling.