NR 217.04(2)(a)2.2. A permittee may request an alternative effluent limitation in cases where the operation of specific biological phosphorus removal technologies will achieve a level of performance equivalent to a 1 mg/L effluent standard. Systems which employ biological phosphorus removal technology shall result in the removal of not less than 90% of the phosphorus which would be removed by achieving the 1 mg/L total phosphorus effluent standard based upon a mass determination. NR 217.04(2)(a)2.a.a. A permittee requesting an alternative effluent limitation under this subdivision shall, as a part of the WPDES permit application process, provide information which demonstrates that achieving the requested alternative effluent limitation using biological phosphorus removal will achieve this requirement. The information shall include data on the total mass of phosphorus discharged using biological removal with and without chemical polishing and the total mass of phosphorus discharged using treatment technologies to achieve the 1 mg/L effluent standard and the information necessary for the department to establish an alternative effluent limitation. NR 217.04(2)(a)2.b.b. The department shall review requests and the information provided by permittees and may establish alternative effluent limitations to the effluent standard imposed under sub. (1) (a) 1., 2., or 4. where the alternative limitation, in the best professional judgment of the department, will result in insignificant differences in the amount of phosphorus discharged, on a mass basis, compared to the mass which would be discharged by achieving the 1 mg/L total phosphorus effluent standard. For these cases, the department shall establish an alternative effluent limitation considering the effluent quality achievable with the application of biological phosphorus removal technologies, taking into account the total phosphorus removal performance on a mass basis. The alternative effluent limitation established by the department under this subparagraph may not exceed 2 mg/L as a monthly average. NR 217.04(2)(a)3.3. A permittee may request an alternative effluent limitation in cases where phosphorus-deficient wastewaters necessitate the addition of phosphorus to a biological treatment system to assure efficient operation and compliance with other effluent limitations. NR 217.04(2)(a)3.a.a. A permittee requesting an alternative effluent limitation under this subdivision shall, as a part of the WPDES application process, provide information which demonstrates that achieving the 1 mg/L total phosphorus effluent standard is not practically achievable and the information necessary for the department to establish an alternative effluent limitation. The information provided shall include but not be limited to the following: the results of a comprehensive phosphorus minimization study to minimize the amount of phosphorus discharged while allowing efficient operation of the wastewater treatment system, a description of actions implemented to reduce the amount of phosphorus discharged, the phosphorus effluent concentrations achievable after phosphorus minimization steps have been implemented, the removal efficiencies and costs associated with alternative treatment technologies which would be necessary to achieve the 1 mg/L effluent standard and the requested alternative limitation. NR 217.04(2)(a)3.b.b. The department shall review requests and the information provided by the permittee and may establish alternative effluent limitations to the effluent standard imposed under sub. (1) (a) 2. where this standard, in the best professional judgment of the department, is not practically achievable. The department shall establish an alternative effluent limitation considering the minimum phosphorus effluent quality achievable while allowing efficient operation of the wastewater treatment system. The alternative effluent limitation established by the department under this subdivision may not exceed 2 mg/L as a monthly average. NR 217.04(2)(b)(b) Permittees subject to sub. (1) (a) 1. or 2. which do not discharge their effluent into the basins of the Great Lakes or the Fox (Illinois) river may request an alternative effluent limitation for total phosphorus according to the provision of this paragraph. NR 217.04(2)(b)1.1. A permittee may request an alternative effluent limitation under this paragraph in cases where achieving the 1 mg/L effluent standard would not result in an environmentally significant improvement in water quality and material progress towards the attainment and maintenance of associated surface water quality standards for the receiving water as established in chs. NR 102 to 104. NR 217.04(2)(b)2.2. A permittee requesting an alternative effluent limitation under this paragraph shall propose for the department’s approval a study plan to identify the receiving waters affected or potentially affected by the discharge, describe how information will be obtained to justify an alternative effluent limitation under this paragraph, and provide the information necessary to establish interim and alternative effluent limitations under this paragraph. This study plan shall be submitted as a part of the WPDES permit application process. The results of the study shall include an evaluation of all point and non-point sources of phosphorus in the watersheds and the impacts of the phosphorus contributions on biological and chemical water quality conditions. Upon review of the study plan, the department may require additional information as deemed necessary and may expand the study to include other watersheds or portions thereof that may be significantly impacted by the permittee’s discharge of phosphorus. NR 217.04(2)(b)3.3. The department may establish an alternative effluent limitation where, in the best professional judgment of the department and based upon the information provided by the permittee pursuant to the study plan and other relevant information, achieving the effluent standard under sub. (1) (a) 1. or 2. would not result in an environmentally significant improvement in water quality and material progress towards the attainment of associated surface water quality standards for the receiving waterbody as established in chs. NR 102 to 104. NR 217.04(2)(b)4.4. An interim effluent limitation and compliance schedule for completing the study shall be imposed in a permit until the request for an exemption from the 1 mg/L effluent standard is approved or denied. The interim effluent limitation shall be equal to the representative concentration of total phosphorus as a monthly average in the effluent based on the information provided by the permittee as a part of the WPDES permit application process. NR 217.04(2)(b)5.5. Alternative effluent limitations established under this paragraph may not exceed the interim effluent limitation established under subd. 4. NR 217.04(3)(3) Analytical methods and laboratory procedures. Methods used for analysis of influent and effluent samples shall be as described in ch. NR 219 unless alternative methods are specified in the WPDES discharge permit. NR 217.04(4)(4) Compliance. The department shall determine and specify a reasonable compliance schedule in the permittee’s WPDES permit if the facility is unable to meet the effluent standard or limitations determined according to this section at the time of permit issuance or reissuance. The date for compliance with this section may not extend beyond 3 years from the date of permit issuance or reissuance, unless the department determines that circumstances beyond the permittee’s control, such as an environmental impact statement, require additional time for compliance. In such circumstances, the date for compliance with this section may not extend beyond 5 years from the date of permit issuance or reissuance. NR 217.04(5)(5) Department determinations. Effluent standards and limitations established under subs. (1) (a) and (2) are not subject to the variance procedure under s. 283.15, Stats. NR 217.04 HistoryHistory: Cr. Register, November, 1992, No. 443, eff. 12-1-92. NR 217.10NR 217.10 Applicability. This subchapter applies to discharges of phosphorus to surface waters of the state from the following point sources: NR 217.10(1)(1) Publicly and privately owned wastewater facilities or treatment works; NR 217.10(2)(2) Noncontact cooling water discharges which contain phosphorus unless 100 percent of the phosphorus in the discharge originates from the receiving water as intake water; NR 217.10(3)(3) Concentrated animal feeding operations that discharge manure or process wastewater from the production area through alternative treatment facilities under s. NR 243.13; and NR 217.10(4)(4) A facility or site that is regulated under ch. NR 216 only where the department has determined that compliance with the standards in chs. NR 151 and 216 are not sufficient to meet phosphorus criteria in s. NR 102.06. NR 217.10 NoteNote: There may be other point sources that are not subject to the procedures in this subchapter, but which are be subject to s. 283.13 (5), Stats., or procedures in other rules (e.g., ch. NR 243 requirements for concentrated animal feeding operations). NR 217.10 HistoryHistory: CR 10-035: cr. Register November 2010 No. 659, eff. 12-1-10. NR 217.11NR 217.11 Definitions. Definitions of terms and the meaning of abbreviations used in this subchapter are as defined in ss. NR 102.03, 106.03, 205.03, 210.03, and 243.03. In addition, for purposes of this subchapter, the following definitions apply: NR 217.11(2)(2) “Adaptive management” means the use of monitoring data and other information at the time of permit reissuance to reassess management decisions and permit requirements. NR 217.11(3)(3) “New discharger” means a point source which was not authorized by a WPDES permit as of December 1, 2010. A new discharger includes a relocation of an outfall to a different receiving water. NR 217.11(4)(4) “Phosphorus impaired water” means a surface water listed on the 303 (d) list that is impaired for phosphorus, nutrients, or diurnal swings of dissolved oxygen. NR 217.11 NoteNote: A surface water may be impaired and placed on the 303 (d) list for a reason other than phosphorus, nutrients, or dissolved oxygen (e.g., mercury), however the procedures in this subchapter only apply to impairments related to phosphorus, nutrients, or diurnal swings of dissolved oxygen.
NR 217.11(5)(5) “Privately owned wastewater facilities or treatment works” means a facility or treatment works owned by a nongovernmental entity that discharges domestic wastewater, commercial wastewater, or industrial wastewater or a combination thereof. NR 217.11(7)(7) “Total maximum daily load” or “TMDL” means the amount of pollutants specified as a function of one or more water quality parameters that can be discharged into a water quality limited segment and still ensure attainment of the applicable water quality standard in a watershed. NR 217.11(8)(8) “US EPA” means the United States Environmental Protection Agency. NR 217.11(9)(9) “WQBEL” means a water quality based effluent limitation. NR 217.11 HistoryHistory: CR 10-035: cr. Register November 2010 No. 659, eff. 12-1-10. NR 217.12(1)(1) Water quality based effluent limitations for phosphorus shall be included in a permit whenever the department determines: NR 217.12(1)(a)(a) The discharge from a point source contains phosphorus at concentrations or loadings which will cause, has the reasonable potential to cause or contribute to an exceedance of the criteria in s. NR 102.06 in either the receiving water or downstream waters; and NR 217.12(1)(b)(b) The technology based effluent limitation or the alternative treatment technology limitation calculated under s. NR 243.13 is less stringent than necessary to achieve the applicable water quality standard for phosphorus in s. NR 102.06. NR 217.12(2)(2) If the technology based limitation expressed as a concentration is more stringent than the water quality based effluent limitation expressed as a concentration under s. NR 217.13, then the technology based limit shall be included in the permit, along with any mass limitations calculated under this subchapter as required under s. NR 217.14 (1) and (3). NR 217.12 HistoryHistory: CR 10-035: cr. Register November 2010 No. 659, eff. 12-1-10. NR 217.13NR 217.13 Calculation of water quality based effluent limitations for phosphorus. NR 217.13(1)(a)(a) The department shall calculate potential water quality based effluent limitations for point source dischargers of phosphorus using the procedures in this section. NR 217.13(1)(b)(b) Water quality based effluent limitations for phosphorus shall be calculated based on the applicable phosphorus criteria in s. NR 102.06 at the point of discharge, except the department may calculate the limitation to protect downstream waters. NR 217.13(2)(a)(a) Limitation calculation. For discharges of phosphorus to flowing streams and rivers, the water quality based effluent limitation shall be calculated using the following conservation of mass equation: Limitation = [(WQC) (Qs+(1-f)Qe) - (Qs- fQe) (Cs)]/Qe
Where:
Limitation = Water quality based effluent limitation (in units of mass per unit of volume),
WQC = The water quality criterion concentration (in units of mass per unit volume) from s. NR 102.06, Qs = Receiving water design flow (in units of volume per unit time) as specified in par. (b),
Qe = Effluent flow (in units of volume per unit time) as specified in par. (c),
f = Fraction of the effluent flow that is withdrawn from the receiving water, and
Cs = Upstream concentration (in units of mass per unit volume) as specified in par. (d).
NR 217.13(2)(b)(b) Receiving water design flow (Qs). Based on the availability of information and the professional judgment of the department, the value of Qs to be used in calculating the effluent limitation for discharges to flowing waters shall be determined using one of the following: NR 217.13(2)(b)1.1. The average minimum 7-day flow which occurs once every 2 years (7-day Q2) based on information derived by the U. S. geological survey or other department approved information source, using data from a representative gauging station with a period of record of at least 10 years. NR 217.13(2)(b)2.2. If provided by the permittee and approved by the department, the average low 30-day flow which occurs once every 3 years (30-day Q3) based on information derived by the U. S. geological survey or other department approved information source, using data from a representative gauging station with a period of record of at least 10 years. NR 217.13(2)(b)3.3. Other flow deemed more representative of flow conditions and approved by the department. NR 217.13(2)(c)1.1. For dischargers subject to ch. NR 210 and which discharge for 24 hours per day on a year-round basis, Qe shall equal the maximum effluent flow, expressed as a daily average, that is anticipated to occur for 12 continuous months during the design life of the treatment facility unless it is demonstrated to the department that this design flow rate is not representative of projected flows at the facility. NR 217.13(2)(c)2.2. For other dischargers not subject to ch. NR 210, Qe shall equal, based on the best professional judgment of the department, one of the following: NR 217.13(2)(c)2.a.a. The maximum effluent flow, expressed as a 365 day rolling average of daily discharges that has occurred for 12 continuous months and represents normal operations. NR 217.13(2)(c)2.b.b. The maximum effluent flow, expressed as a 30 day rolling average, which has occurred for 30 continuous days and represents normal operations. NR 217.13(2)(c)3.3. For seasonal discharges, discharges proportional to stream flow, or other non-continuous discharge situations, Qe shall be determined on a case by case basis. NR 217.13(2)(d)(d) Upstream concentrations (Cs). The representative upstream concentration of phosphorus shall be used in specific water quality based effluent limit calculations. The representative upstream concentration shall be a concentration derived by the department based on data from the specific stream or from a similar location. Where data are collected on the upstream location, the site’s upstream concentration shall be calculated as a median using the procedures specified in s. NR 102.07 (1) (b) to (c). Neither the two-sided 80 percent confidence interval around the median specified in s. NR 102.07 (2) nor the combined assessment procedures specified in s. NR 102.60 are applicable for purposes in this paragraph. Upstream concentrations may not be measured at a location within the direct influence of a point source discharge. The determination of upstream concentrations shall be evaluated at each permit reissuance. NR 217.13 NoteNote: The department has guidance on collection methods for ambient water sampling and may develop guidance for the evaluation of representative data. The guidance may be obtained from the offices of the department of natural resources, bureau of water quality at 101 South Webster Street, P.O. Box 7921, Madison, Wisconsin 53707.
NR 217.13(3)(3) Discharges to inland lakes and reservoirs. For discharges of phosphorus directly to inland lakes, reservoirs, and other receiving waters which do not exhibit a unidirectional flow at the point of discharge, the department shall set the effluent limit equal to the criterion for the receiving water or the downstream water. NR 217.13 NoteNote: As described in s. NR 217.16, effluent limitations for discharges to lakes may also be based on the wasteload allocation of a total maximum daily load, where the total maximum daily load has been approved by US EPA. NR 217.13(4)(4) Discharges directly to Great Lakes. For discharges directly to the Great Lakes, the department shall set effluent limits consistent with nearshore or whole lake model results approved by the department. The department may set an interim effluent limit based on the best readily available phosphorus removal technology commonly used in Wisconsin. NR 217.13 NoteNote: At the time this rule was promulgated, December 1, 2010, the best readily available phosphorus removal technology indicates a limit of 0.6 mg/L.
NR 217.13(5)(5) Other methods of limit calculation. The department may use other models and equations for calculating a water quality based effluent limitation if, in the best professional judgment of the department, the model provides a more accurate representation of the conditions. NR 217.13(6)(a)(a) Except as provided in par. (b), whenever the department determines that more than one discharge may be affecting the water quality of the same receiving water, the resultant combined allowable load shall be divided among the various discharges using an allocation method based on site-specific considerations. Whenever the department makes a determination under this subsection, the department shall notify all permittees who may be affecting the water quality of the same receiving water of the determination and any limitations developed under this subsection. Permittees shall be given the opportunity to comment to the department on any determination made under this subsection. NR 217.13(6)(b)(b) This subsection does not apply if there is a US EPA approved TMDL for phosphorus for the receiving water. If there is a US EPA approved TMDL, the combined allowable load shall be divided in accordance with the approved TMDL. NR 217.13(7)(7) Minimum effluent limitations. If the water quality based effluent limitation calculated pursuant to the procedures in this section is less than the phosphorus criterion specified in s. NR 102.06 for the water body, the effluent limit shall be set to be equal to the criterion. NR 217.13(8)(8) New dischargers. If a new discharger is proposing a discharge of phosphorus to a receiving or downstream water that is a phosphorus impaired water, the new discharger may not discharge phosphorus except as follows: NR 217.13(8)(a)(a) The new discharge of phosphorus is allocated part of the reserve capacity or part of the wasteload allocation in a US EPA approved TMDL; NR 217.13(8)(b)(b) The new discharger can demonstrate the new discharge of phosphorus will improve water quality in the phosphorus impaired segment; or NR 217.13(8)(c)(c) The new discharger can demonstrate that the new phosphorus load will be offset through a phosphorus trade or other means with another discharge of phosphorus to the 303 (d) listed water. The offset must be approved by the department and must be implemented prior to discharge. NR 217.13 NoteNote: Section 283.84, Stats., establishes requirements for pollutant trades. NR 217.13 HistoryHistory: CR 10-035: cr. Register November 2010 No. 659, eff. 12-1-10; CR 19-094: am. (2) (d) Register September 2022 No. 801, eff. 10-1-22; correction in (2) (d) made under s. 35.17, Stats., Register September 2022 No. 801. NR 217.14NR 217.14 Expression of limitations. NR 217.14(1)(a)(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:
