NR 106.145(9)(c)3.3. If at least 3 field blanks are collected on a day when samples are collected and the average mercury concentration of the field blanks plus 2 standard deviations is less than or equal to one-half of the level in the associated sample or less than the lowest water quality criterion for mercury found in ch. NR 105, whichever is greater, results may be used. NR 106.145 NoteNote: As of November 1, 2002 the lowest water quality criterion listed in ch. NR 105 is 1.3 ng/L. NR 106.145(9)(c)4.4. Once a permittee demonstrates the ability to collect samples from a given site using an established procedure that meets the use-criteria of subd. 2., the permittee may decrease the number of field blanks to no fewer than one field blank for each 4 sampling days. NR 106.145(9)(c)4.a.a. The initial demonstration shall consist of at least 6 consecutive sampling days. NR 106.145(9)(c)4.b.b. If the permittee makes significant changes to the sampling procedure or sampling personnel, the 6-day demonstration shall be repeated. NR 106.145(9)(c)4.c.c. If after reducing the field blank frequency, a field blank fails to meet the use-criteria, the permittee shall take corrective action and return to collecting field blanks on each sampling day until it can meet the use-criteria for at least 3 consecutive sampling days. NR 106.145(9)(c)4.d.d. In no case may the permittee decrease field blanks to fewer than one for each 10 samples. NR 106.145(9)(c)5.5. The permittee shall report, but may not subtract, field blank concentrations when reporting sample results. NR 106.145 NoteNote: When using the data, the department may subtract field blanks from sample concentrations on a case-by-case basis.
NR 106.145 NoteNote: “Matrix spike” has the meaning specified in EPA Method 1631, Revision E: Mercury in Water by Oxidation, Purge and Trap, and Cold Vapor Atomic Fluorescence Spectrometry, August 2002, Office of Water, EPA-821-R-02-019.
NR 106.145(10)(b)(b) The analytical method used shall be sensitive enough to quantify mercury concentrations in the sample or mercury concentrations down to the lowest water quality criterion found in ch. NR 105, whichever is greater. NR 106.145(10)(c)(c) The department may exempt a permittee from the sensitivity requirement in par. (b) if the permittee can demonstrate to the department’s satisfaction that the specific effluent matrix does not allow this level of sensitivity using the most sensitive approved method with all reasonable precautions. NR 106.145(10)(d)(d) The laboratory performing the analyses shall be certified for mercury under the cold vapor atomic fluorescence spectrophotometry technology of ch. NR 149. NR 106.145(10)(e)(e) Method blanks analyzed concurrently with samples shall be reported with sample results. Method blanks may be subtracted from sample results unless concentrations of mercury in the method blank exceed the laboratory’s limit of detection, 0.5 ng/L or 5% of the sample concentration, whichever is greater. NR 106.145(10)(f)(f) Matrix spikes analyzed concurrently with samples shall have recoveries between 71 and 125%. NR 106.145(11)(11) Data rejection. The department may reject any sample results if data quality requirements specified in subs. (9) and (10) are not met or if results are produced by a laboratory that is not in compliance with requirements specified in ch. NR 149. NR 106.145(12)(12) Applicability of the variance process under s. 283.15, Stats. If a water quality based effluent limitation is included in a permit under sub. (6) (b), a permittee may apply to the department for a variance from the water quality standard used to derive the limitation following the procedure specified in s. 283.15, Stats. Where a permittee has been granted an alternative mercury effluent limitation under this section, the procedures of s. 283.15, Stats., are not applicable. NR 106.145 HistoryHistory: CR 02-019: cr. Register October 2002 No. 562, eff. 11-1-02; corrections in (10) (d) made under s. 13.92 (4) (b) 7., Stats., Register July 2010 No. 655; CR 15-084; am. (1) (b), (2) (title), consol. (2) (b) (intro.) and 1. and renum. (2) (bm) and am., r. (2) (b) 2. Register August 2016 No. 728, eff. 9-1-16; CR 17-046: am. (10) (a), (d), (11) Register February 2021 No. 782, eff. 6-29-21. NR 106.15NR 106.15 Limitations for mercury. Regardless of the effluent limitations determined under this chapter, the discharge of organic mercury compounds, inorganic mercury compounds, and metallic mercury shall not exceed the requirements in s. 281.17 (7), Stats., and ch. NR 100. NR 106.15 HistoryHistory: Cr. Register, February, 1989, No. 398, eff. 3-1-89. NR 106.30NR 106.30 Applicability. The provisions of this subchapter are applicable to point sources that discharge wastewater containing ammonia to surface waters of the state. This subchapter first applies to permits issued or reissued after March 1, 2004. NR 106.30 NoteNote: Any discharges of ammonia from a concentrated animal feeding operation (CAFO) are regulated under ch. NR 243. NR 106.30 HistoryHistory: CR 03-050: cr. Register February 2004 No. 578, eff. 3-1-04. NR 106.31NR 106.31 Definitions. In this subchapter: NR 106.31(3)(3) “Early life stages” or “ELS” means the life stages of fish that include the pre-hatch embryonic period, post-hatch free embryo or yolk-sac fry, and the larval period, during which the fish feeds. Juvenile fish, which are anatomically similar to adults, are not considered an early life stage. The duration of the early life stage extends from the beginning of spawning through the end of the larval period. NR 106.31(4)(4) “Early life stages absent” means the early life stages of fish are not present in a water body affected by a permittee’s discharge. NR 106.31(5)(5) “Early life stages present” means the early life stages of fish are present in a water body affected by a permittee’s discharge. NR 106.31(6)(6) “Lagoon system” means a wastewater treatment system where the method of treatment consists of intermediate-depth basins with typical detention times of 30 to 60 days and generally a continuous discharge. Sufficient aeration is provided to help satisfy oxygen demand, but not provide for complete mixing. NR 106.31(7)(7) “Real-time” means an event that is occurring during a present point in time. NR 106.31(8)(8) “Stabilization pond” means a wastewater treatment system consisting of large shallow earthen basins that use algae and aerobic, facultative, and anaerobic organisms for wastewater treatment. Stabilization ponds include, but are not limited to, those sized for a minimum of 150 days storage and have discharges in the spring and fall. NR 106.31(9)(9) “WPDES” or “WPDES permit” means Wisconsin pollutant discharge elimination system permit under ch. 283, Stats. NR 106.31 HistoryHistory: CR 03-050: cr. Register February 2004 No. 578, eff. 3-1-04. NR 106.32NR 106.32 Calculation of water quality-based effluent limitations for ammonia. NR 106.32(1)(a)(a) The department shall establish water quality based effluent limitations for point source dischargers of ammonia whenever the limitations are necessary, as determined by any method in this section, to meet the applicable water quality standards and criteria in chs. NR 102 to 105. NR 106.32(1)(b)(b) Water quality based effluent limitations for ammonia shall be determined to attain and maintain water quality standards and criteria specified in or determined according to procedures in ch. NR 105, at the point of discharge. Effluent limitations shall be established to protect downstream waters whenever the department has information to make the determinations. NR 106.32(2)(a)(a) The department shall establish daily maximum water quality based effluent limitations to ensure that ammonia is not present in amounts that are acutely harmful to aquatic life in all surface waters, including those portions of the mixing zone normally habitable by aquatic life as required by s. NR 102.04 (1). NR 106.32(2)(b)(b) To assure compliance with par. (a) and except as provided in pars. (c) and (e), water quality-based effluent limitations for ammonia shall equal the final acute value as determined in s. NR 105.05 for the respective fish and aquatic life subcategory for which the receiving water is classified. The water quality-based limitations based on acute toxicity shall be established using all of the following methods: NR 106.32(2)(b)1.1. Effluent limitations for ammonia for discharges to water bodies classified as cold water communities shall be established using the ammonia criteria for the CW Category 1, shown in ch. NR 105, Table 2C, except as provided in subd. 2. NR 106.32(2)(b)2.2. If the permittee can demonstrate to the department through site specific information that the fish present in the receiving water are limited to those included in CW Category 2, CW Category 3, or CW Category 5, as described in ch. NR 105, Table 2C, then effluent limitations shall be established based on the criteria shown in ch. NR 105 Table 2C for the respective CW Category. If the department grants approval for an alternative limitation based on CW Category 2, 3, or 5, the department shall include the alternative limit in a modified or reissued permit provided antidegradation requirements in ch. NR 207 have been satisfied. NR 106.32(2)(b)3.3. In all cases, effluent limitations for ammonia for discharges directly to Lake Superior, Lake Michigan and Green Bay north of 44° 32’ 30” north latitude shall be established using the ammonia criteria for the CW Category 1 shown in ch. NR 105, Table 2C. NR 106.32(2)(c)(c) Water quality based effluent limitations for ammonia may exceed the final acute value within a zone of initial dilution that meets all of the conditions in s. NR 106.06 (3) (c). NR 106.32(2)(d)(d) Effluent limitations for ammonia shall be calculated using the pH value of the effluent as determined in sub. (4) (b) and this paragraph. The department may also establish effluent limitations or other requirements for pH according to the following procedure: NR 106.32(2)(d)1.1. Whenever the department establishes an effluent limitation based on the acute ammonia criteria in ch. NR 105, the department may also establish a maximum effluent limitation for pH equal to the pH value that was used to calculate the ammonia effluent limitation. NR 106.32(2)(d)2.2. The department may allow a permittee to chemically adjust effluent pH to a lower value for the purpose of obtaining a higher ammonia effluent limitation. The adjusted pH shall be used to calculate the ammonia effluent limitation. The pH value of an effluent may not be adjusted to less than 6.0. Whenever the effluent pH is adjusted, the department may require continuous monitoring of the pH of the effluent. NR 106.32(2)(d)3.3. The department may establish an alternative pH for calculating the limitation under this section to protect downstream uses whenever the receiving water pH is significantly different from the effluent, or if a zone of initial dilution is applicable based on par. (c). NR 106.32(2)(e)(e) To assure compliance with par. (a), the department may calculate acute water quality-based effluent limitations using the following procedure if the department concludes that limitations calculated in par. (b) or (c) are not sufficiently protective of fish and aquatic life. The department may include the calculated WQBEL in a permit if this limitation is more stringent than the limitation calculated in par. (b) or (c): Limitation = (WQC) (Qs+(1-f)Qe) - (Qs- fQe) (Cs)
Qe
NR 106.32(3)(3) Limitations based on chronic toxicity or long-term impacts. NR 106.32(3)(a)(a) Water quality criteria. The department shall calculate water quality based effluent limitations for ammonia to ensure that the chronic toxicity criteria applicable to the receiving water as specified in chs. NR 102 to 105 will be met after taking into account dilution with an appropriate quantity of receiving water flow allowed in this subsection. The available dilution shall be determined according to par. (c) unless the conditions specified in s. NR 102.05 (3) require less dilution or no dilution be allowed. The chronic toxicity criteria to be used in the calculation of ammonia effluent limitations shall apply as follows: NR 106.32(3)(a)1.1. The applicable early life stages present ammonia criteria in s. NR 105.05 Table 4B shall be used to calculate effluent limitations for all times of the year for all discharges to Class I and Class II trout waters, as identified by the department’s Wisconsin Trout Streams publication referenced in s. NR 102.04 (3) (a), and any additional Class I and Class II trout waters identified in ss. NR 102.10 (1) (d) and (e), and 102.11 (1) (b) and (c). NR 106.32(3)(a)2.2. The applicable early life stages present ammonia criteria in s. NR 105.05 Table 4B shall be used to calculate effluent limitations for all discharges to all waters supporting warm water sport fish and warm water forage fish during the month of April or whenever the receiving water temperature, as determined in s. NR 106.32 (4), is greater than or equal to 14.6 degrees Celsius. NR 106.32 NoteNote: Effluent limitations are determined based on monthly average water temperatures determined from historical records. For many waters supporting warmwater fish species, the monthly average water temperature is 14.6 degrees Celsius or greater during the months of May through September.
NR 106.32(3)(a)3.3. Except as provided in subd. 4., the applicable early life stage absent ammonia criteria in s. NR 105.05 Table 4B shall be used to calculate effluent limitations for all discharges to all waters supporting warm water sport fish and warm water forage fish whenever the receiving water temperature, as determined in s. NR 106.32 (4), is less than 14.6 degrees Celsius, but not including the month of April. NR 106.32(3)(a)4.4. The applicable early life stages present ammonia criteria in s. NR 105.05 Table 4B shall be used to calculate effluent limitations applicable for the months of January, February, and March for all discharges to waters where the department determines that early life stages of burbot are present. NR 106.32 NoteNote: Burbot are not present in limited aquatic life streams, limited forage fish streams and small or shallow headwater streams and rivers.
NR 106.32(3)(a)4.a.a. Whenever the department determines that early life stage present ammonia criteria are applicable under this subdivision, the permittee may make a demonstration that the early life stages of burbot are not present at the discharge location and will not be affected by the discharge during the months of January and February. If the department grants approval for an alternative limitation based on results of this study, the department shall include the alternative limitation in a permit modification or reissuance provided antidegradation requirements in ch. NR 207 have been satisfied. NR 106.32(3)(a)4.b.b. If the permittee can demonstrate to the satisfaction of the department that the early life stages of burbot are not present at the discharge location and will not be affected by the discharge, the early life stage absent ammonia criteria in s. NR 105.05 Table 4B shall be used to calculate effluent limitations that apply to the permittee and the department shall propose a permit modification to incorporate the limitations. If the permittee does not make a sufficient demonstration, the early life present ammonia criteria in s. NR 105 Table 4B shall apply. NR 106.32(3)(a)5.5. The applicable early life stages present ammonia criteria in s. NR 105.05 Table 4B shall be used to calculate effluent limitations for the months of May through September for all discharges to waters designated in ch. NR 104 as limited forage fish waters. The early life stages absent ammonia criteria in s. NR 105.05 Table 4B shall be used to calculate effluent limitations for the months of October through April for all discharges to waters designated in ch. NR 104 as limited forage fish waters. NR 106.32(3)(a)6.6. The applicable ammonia criteria in s. NR 105.05 Table 4B shall be used to calculate effluent limitations for all discharges to waters designated in ch. NR 104 as limited aquatic life waters. NR 106.32(3)(b)(b) Calculation of limits. Water quality based effluent limitations to meet the requirements of this subsection shall be calculated using the procedure specified in subd. 1. or 2., except as provided in s. NR 106.06 (6). NR 106.32(3)(b)1.1. For discharges of ammonia to flowing receiving waters, the water quality based effluent limitation shall be calculated using the following conservation of mass equation whenever the background concentration is less than the water quality criterion: Limitation = (CTC) (Qs + (1-f)Qe) - (Qs - fQe) (Cs)
Qe
Where:
Limitation = Water quality based effluent limitation (in units of mass per unit of volume)
CTC = The chronic toxicity criterion (concentration in units of mass per unit volume) as referenced in par. (a)
Qs = Receiving water design flow (in units of volume per unit time) as specified in par. (c)
Qe = Effluent flow (in units of volume per unit time) as specified in par. (d)
f = Fraction of the effluent flow that is withdrawn from the receiving water
Cs = Background concentration of ammonia (in units of mass per unit volume) as specified in par. (e)
NR 106.32 NoteNote: In applying this equation, all units for the flow and concentration parameters respectively shall be consistent.
NR 106.32(3)(b)2.2. For discharges of ammonia to receiving waters which do not exhibit a unidirectional flow at the point of discharge, such as lakes or impoundments, the department may calculate, in the absence of specific data, water quality based effluent limitations using the following equation whenever the background concentration is less than the water quality criterion: Limitation = 11 (CTC) - 10Cs
Where:
Limitation = Water quality based effluent limitation (in units of mass per unit of volume)
CTC = The chronic toxicity criterion (concentration in units of mass per unit volume) as referenced in par. (a)
Cs = Background concentration of ammonia (in units of mass per unit volume) as specified in par. (e)
NR 106.32(3)(b)3.3. On a case-by-case basis other dilutional factors may be used, but in no case may the dilution allowed exceed an area greater than the area where discharge induced mixing occurs. The discharge is also subject to the conditions specified in s. NR 102.05 (3). The permittee may be required to determine the size of the mixing zone using models or dye studies that are determined to be acceptable by the department. NR 106.32(3)(c)(c) Receiving water design flow (Qs). Subject to the application of the zone of passage factors in subd. 3. or 4., the value of Qs to be used in calculating the effluent limitation for discharges to flowing waters shall be determined using one of the approaches in subd. 1. or 2. NR 106.32(3)(c)1.1. To calculate limits based on 4-day chronic ammonia criteria, Qs shall equal the average minimum 7-day flow which occurs once in 10 years (7-day Q10) or, if sufficient information is available to calculate a biologically based receiving water design flow, the flow which prevents an excursion from the criterion using a duration of 4 days and a frequency of less than once every 3 years (4-day, 3-year biological flow). To calculate limits based on 30-day chronic ammonia criteria, Qs shall equal the average minimum 30-day flow which occurs once in 5 years (30-day Q5) or 85% of the average minimum 7-day flow which occurs once in 2 years (7-day Q2). NR 106.32(3)(c)2.2. If approved by the department, the value of Qs of the receiving water for calculating effluent limitations based upon the chronic toxicity criteria specified in s. NR 105.06 may be determined on a case-by-case basis, using historical flow data or real time data. Qs may be based on real-time streamflow data if the permittee demonstrates that modifications to effluent quality or quantity can be achieved in response to changing stream conditions. Appropriate modifications to effluent quality or quantity may include, but are not limited to, land application, storage, shutdown or reduction in ammonia feed rates. NR 106.32(3)(c)3.3. To provide for an adequate zone of passage, the value of Qs to be used in the equation in par. (b) 1. shall be determined by multiplying the applicable value from subd. 1. or 2. by the following zone of passage factors:
