Section NR 119.03 - Less stringent SSC A waterbody or segment may be eligible for a less stringent SSC if the requestor demonstrates and the department determines that the designated uses of the waterbody and its affected downstream waters can be protected by a less stringent phosphorus criterion based on the analysis of site-specific data. For the department to approve a less stringent SSC, the SSC shall be developed using methods specified in ss. NR 119.05 to 119.06 and be protective of downstream uses as specified in s. NR 119.06 (6). The categories of waterbodies that may qualify for less stringent SSC include all of the following:
(1) BIOLOGICAL METRICS ATTAINED. A less stringent SSC may be appropriate for a waterbody that is not attaining its statewide phosphorus criterion if all of its phosphorus response indicators and biological assessment thresholds are attained.(2) BIOLOGICAL METRICS NOT ATTAINED. A less stringent SSC may be appropriate for a waterbody that is not attaining its statewide phosphorus criterion even if one or more of its phosphorus response indicators or biological assessment thresholds are not attained, provided a modeling analysis demonstrates that the phosphorus response indicators are expected to be attained if the waterbody's phosphorus concentration is sufficiently reduced to attain a proposed SSC that is less stringent than the statewide phosphorus criterion. Note: Certain reservoirs with a statewide phosphorus criterion of 30-40 ug/L may fit in this category. An example of this analysis is the modeling and analysis conducted for Petenwell and Castle Rock Lakes.
(3) HIGH NATURAL BACKGROUND PHOSPHORUS CONCENTRATION. A less stringent SSC may be appropriate if a waterbody is not attaining the statewide phosphorus criterion because the natural background phosphorus concentration is higher than the statewide phosphorus criterion.Wis. Admin. Code Department of Natural Resources NR 119.03
Adopted by, CR 19-093: cr. Register September 2022 No. 801, eff. 10/1/2022