Water Quality Standards Rule Updates
The DNR is conducting rulemaking on several topics related to surface water quality standards, outlined below.
Rules in Progress
Antidegradation (WY-13-20)
DNR is proposing updates to its antidegradation policy in ch. NR 102.05(1), which is meant to protect high-quality waterbodies from decreasing water quality. Procedures for implementing this policy through the department's permitting programs are also being updated at ch. NR 207, Subchapter I, and ch. NR 216.
Recently Promulgated Water Quality Standards Rules
The following water quality standards regulations are now in effect (effective date shown in parentheses).
Lac Courte Oreilles site-specific phosphorus criteria (2-2024). A more stringent site-specific phosphorus criterion was adopted for Lac Courte Oreilles (LCO), a lake in Sawyer County. The revision changes the lake's total phosphorus criterion from 15 ug/L to 10 ug/L to support the lake's coldwater fish community.
- The 2022 Technical Support Document describes and supports the proposed rule.
- The 2022 Technical Support Document cross-references previous materials from a similar 2019 rule: 2018 Technical Support Document with 2019 Addendum.
Assessing waterbodies using biological metrics (10-2022). A new subchapter III was established in ch. NR 102 outlining how waterbodies are assessed and establishing biological assessment thresholds and phosphorus response indicators.
Process for developing site-specific criteria for phosphorus (10-2022). A new rule ch. NR 119 was created establishing a process for developing site-specific criteria for phosphorus.
PFAS surface water criteria (8-2022). Surface water criteria were established for poly- and perfluoroalkyl substances. The following rules were updated: ch. NR 102.04(8)(d), ch. NR 105, ch. NR 106 and ch. NR 219.
Site-specific phosphorus criteria for lakes in the Wisconsin River Basin (6-2020). Phosphorus criteria specific to Petenwell Lake, Castle Rock Lake, and Lake Wisconsin were promulgated in ch. NR 102.06(7)(b). The site-specific criteria were developed in conjunction with the Wisconsin River Basin Total Maximum Daily Load (TMDL) analysis, and the site-specific criteria analysis can be found in Appendix C of the TMDL documentation.
Bacteria water quality criteria (4-2020). Water quality criteria for bacteria were revised from fecal coliform criteria to E. coli criteria, to better protect public health and recreation, in ch. NR 102.04(6)(a). Wastewater disinfection requirements were updated to reflect the new criteria at ch. NR 210.06.