Section NR 217.14 - Expression of limitations(1) GENERAL. (a) Water quality based effluent limitations, when required pursuant to s. NR 217.15, shall be expressed in a discharge permit as a concentration. A mass limit shall also be included in a permit for discharges of phosphorus to any of the following receiving or downstream waters: 2. An outstanding or exceptional resource water, as designated in ss. NR 102.10 and 102.11;3. A phosphorus impaired water; or4. A surface water that has an approved TMDL for phosphorus.(b) The department may establish mass limitations in permits for any other discharges of phosphorus if a concentration limit for phosphorus is included in the permit, and where an increase in phosphorus load is likely to result in adverse effects on water quality in the receiving water or downstream water.(c) For discharges to lakes, the department shall also include an annual mass limit for phosphorus in the permit.(d) If there is a US EPA approved TMDL for the receiving water, the department shall include a mass limit expressed in the manner consistent with the requirements of the TMDL. As provided in s. NR 217.16, this TMDL based mass limit may be included in the permit in addition to, or in lieu of the mass limit established pursuant to this section. Note: In accordance with s. 283.84, Stats., the department may approve the use of phosphorus trading as a means for a point source to achieve compliance with the water quality based effluent limitation, including a TMDL based limitation. The trade shall be incorporated into the terms of the WPDES permit for the point source and must be approved by the department prior to implementation.
(2) CONCENTRATION BASED LIMITATIONS . Concentration effluent limitations calculated under s. NR 217.13 shall be expressed as a monthly average in permits, except for concentrations of less than or equal to 0.3 mg/L for which limitations may be expressed as six-month averages. If a concentration limitation expressed as a six-month average is included in a permit, a monthly average concentration limitation equal to three times the water based effluent limitation calculated under s. NR 217.13 shall also be included in the permit.(3) MASS BASED LIMITATIONS. Concentration effluent limitations calculated under s. NR 217.13 shall be converted into mass effluent limitations using the effluent flow identified in s. NR 217.13 and an appropriate conversion factor, and expressed as a monthly average in the permit, except for concentration based limitations of less than or equal to 0.3 mg/L for which mass limitations may be expressed as six-month averages.Wis. Admin. Code Department of Natural Resources § NR 217.14
CR 10-035: cr. Register November 2010 No. 659, eff. 12-1-10.Amended by, CR 15-085: am. (2), (3) Register August 2016 No. 728, eff. 9/1/2016