NR 106.08(6)(b)1.1. If a zone of initial dilution has not been approved by the department, the potential to exceed an acute criterion shall be calculated using the following equation: (TUa effluent) (B) > 1.0
NR 106.08(6)(b)2.2. If a zone of initial dilution has been approved by the department, the potential to exceed an acute criterion shall be calculated using the following equation: [(TUa effluent) (B) (AMZ)] > 1.0
NR 106.08(6)(b)3.3. The potential to exceed a chronic criterion shall be calculated using the following equation: [(TUc effluent) (B) (IWC)]> 1.0
NR 106.08(6)(c)(c) Reasonable potential multiplication factor. The department shall use the reasonable potential multiplication factor in par. (b) to convert the calculated effluent toxicity value to the estimated 95th percentile toxicity value. The department shall use all of the following methods to select a reasonable potential multiplication factor: NR 106.08(6)(c)1.1. When there are less than 10 individual toxicity detects, the multiplication factor shall be taken from Table 4 and based on a coefficient of variation of 0.6. NR 106.08(6)(c)2.2. When there are 10 or more individual toxicity detects, the multiplication factor shall be taken from Table 4 and based on coefficient of variation calculated as the standard deviation of the WET test endpoints, IC25, IC50, or LC50, divided by the arithmetic mean of the WET tests. Table 4 — Reasonable Potential Multiplication Factor
NR 106.08(6)(d)(d) Maximum toxicity values. The department shall set the TUc effluent and TUa effluent values in par. (b) equal to zero whenever toxicity is not detected or the LC50, IC25, or IC50 equals or exceeds 100% effluent. NR 106.08(6)(e)(e) Exception. WET limits are not necessary under this subsection when the department determines chemical-specific limits for the effluent are sufficient to attain and maintain applicable numeric and narrative water quality standards, taking into consideration all of the following: NR 106.08(6)(e)2.2. Controls on the pollutant discharged by nonpoint source pollution in the watershed. NR 106.08(6)(e)3.3. The variability of the pollutant or parameter in the effluent discharged. NR 106.08(6)(e)4.4. Sensitivity of species to toxicity testing when evaluating whole effluent toxicity as defined in s. NR 106.03. NR 106.08(6)(f)(f) Fact sheet. If the department determines WET limitations are not necessary under par. (e), all of the factors that are required for the determination must be specifically discussed in the fact sheet for the permit. NR 106.08(7)(7) Data Exclusions. The department may exclude data from a WET reasonable potential determination when those data meet any of the following conditions: NR 106.08(7)(b)(b) Positive WET results are caused by deficiency toxicity only. NR 106.08(7)(c)(c) Positive WET results are caused by groundwater or surface water remediation needed to correct or prevent an existing surface or groundwater contamination situation or a public health problem. NR 106.08 HistoryHistory: Cr. Register, February, 1989, No. 398, eff. 3-1-89; am. (1), r. and recr. (5), Register, August, 1997, No. 500, eff. 9-1-97; CR 09-123: am. (5) (a) Register July 2010 No. 655, eff. 8-1-10; correction in (4) made under s. 13.92 (4) (b) 7., Stats., Register July 2010 No. 655; CR 15-085: r. and recr. Register August 2016 No. 728, eff. 9-1-16; CR 17-002: cr. (6) (e), (f) Register April 2018 No. 748, eff. 5-1-18. NR 106.09NR 106.09 Whole effluent toxicity data evaluation and limitations. NR 106.09(1)(1) Data evaluation. Data evaluation procedures are specified in the whole effluent toxicity test methods specified in s. NR 219.04, Table A. In the event of a WET test failure, facility specific requirements shall be established in the WPDES permit which specify required follow-up actions. NR 106.09(2)(a)(a) Except as provided in par. (c), the department shall establish acute whole effluent toxicity limitations to ensure that substances shall not be present in amounts which are acutely harmful to aquatic life in all surface waters including the mixing zone and effluent channel as required by s. NR 102.04 (1). NR 106.09(2)(b)(b) To assure compliance with par. (a), a whole effluent toxicity test may not result in a statistically valid LC50 less than 100% with the following taxa-specific exposure periods: NR 106.09(2)(b)1.1. 48 hours for aquatic invertebrate organisms (including Ceriodaphnia dubia); NR 106.09(2)(b)2.2. 96 hours for aquatic vertebrate organisms (including fathead minnows (Pimephales promelas)); NR 106.09(2)(b)3.3. Any other exposure period deemed appropriate by the department for a specific test organism. NR 106.09(2)(c)(c) If a zone of initial dilution is determined appropriate in accordance with the provisions of s. NR 106.06 (3) (c), whole effluent acute toxicity limitations determined by this subsection shall be adjusted such that the effluent meets the following condition. The adjustment shall insure that after dilution of the effluent with the receiving water at a concentration equal to 3.3 times the percent dilution value calculated through application of the zone of initial dilution, the test solution of effluent and receiving water shall not produce a statistically valid LC50 less than 3.3 times the percent dilution value determined through application of the zone of initial dilution with the exposure periods as provided in par. (b). NR 106.09(2)(d)(d) If, in the judgment of the department, the statistical interpretation methods used to test for LC50 are not appropriate for a specific data set, empirical interpretation methods may be used to determine the significance of an effect. NR 106.09(2)(e)(e) Acute whole effluent toxicity limits shall be expressed as 1.0 TUa unless an AMZ is approved in which case these limits shall be expressed as a value that is 100 divided by the AMZ. Compliance with an acute whole effluent toxicity water quality-based limitation shall be determined by comparing the TUa endpoint from each toxicity test to the limitation. Pursuant to s. NR 106.08 (6) (d) a calculated LC50 that exceeds 100% is set equal to zero. NR 106.09 NoteNote: A toxicity reduction evaluation study is not always required in the event an acute WET limit is imposed in a permit.
NR 106.09(2)(f)(f) Whole effluent acute toxicity limitations shall be expressed in permits as daily maximum limitations. NR 106.09(3)(a)(a) The department shall establish chronic whole effluent toxicity limitations to ensure that concentrations of substances are not discharged from a point source that alone or in combination with other materials present are toxic to fish or other aquatic life as required by s. NR 102.04 (4) (d). NR 106.09(3)(b)(b) To assure compliance with par. (a), an effluent, after dilution with an appropriate allowable quantity of receiving water flow equivalent to that provided by receiving water flows specified in s. NR 106.06 (3) (c) or implied in s. NR 106.06 (3) (b) 2., may not cause a significant adverse effect to a test organism population when compared to an appropriate control, as determined by applying all of the following: NR 106.09(3)(b)1.1. Using statistical interpretation methods appropriate to the toxicity test protocol, an adverse effect will be determined to be significant if the statistically derived IC25 or IC50, as specified for each species in the whole effluent toxicity test methods required in s. NR 219.04, Table A, from the whole effluent toxicity test, is less than the calculated IWC. NR 106.09(3)(b)2.2. If, in the judgment of the department, the statistical interpretation methods used to test for significance are not appropriate for a specific data set, empirical interpretation methods may be used to determine the significance of an effect. NR 106.09(3)(c)(c) Chronic whole effluent toxicity limits shall be expressed as a value that is 100 divided by the IWC. Compliance with a chronic whole effluent toxicity water quality-based limitation shall be determined by comparing the monthly average calculated TUc from all toxicity tests conducted during that month to the limitation. Pursuant to s. NR 106.08 (6) (d), a calculated IC25 or IC50 that exceeds 100% is set equal to zero. NR 106.09 NoteNote: A toxicity reduction evaluation study is not always required in the event a chronic WET limit is imposed in a permit.
NR 106.09(3)(d)(d) Whole effluent chronic toxicity limitations shall be expressed in permits as monthly average limitations. NR 106.09 HistoryHistory: Cr. Register, February, 1989, No. 398, eff. 3-1-89; renum. (1) (a), (b), (c) (intro.) and 2. and (2) to be (2) (a) to (c) and (3) and am. (2) (b), (c), (3) (a), (b) (intro.) and 1., r. (1) (c) 1., cr. (1), Register, August, 1997, No. 500, eff. 9-1-96; CR 03-050: am. (2) (b) (intro.) Register February 2004 No. 578, eff. 3-1-04; CR 04-101: am. (1) Register May 2005 No. 593, eff. 6-1-05; CR 15-085: r. and recr. (2) (e), cr. (2) (f), am. (3) (b) (intro.), 1., r. and recr. (3) (c), cr. (3) (d) Register August 2016 No. 728, eff. 9-1-16. NR 106.10NR 106.10 Noncontact cooling water additives. The department shall establish water quality based effluent limitations for toxic and organoleptic substances in noncontact cooling water discharges as follows: NR 106.10(1)(1) For toxic and organoleptic substances commonly added by suppliers of drinking water systems and present in the noncontact cooling water, a water quality based effluent limitation calculated under s. NR 106.06 that is based on the applicable water quality criterion or secondary value shall be included in the permit unless the permittee demonstrates at least one of the following: NR 106.10(1)(a)(a) The concentration of the substance in the intake water is dissipated within the system that supplies the intake water to the permittee and is consistently less than the water quality based effluent limitation. NR 106.10(1)(b)(b) An effluent limitation is not necessary as determined using the reasonable potential procedures in s. NR 106.05. NR 106.10(1)(c)(c) Prior to reaching the receiving water, the substance dissipates or is removed to a level that is below the water quality based effluent limitation. NR 106.10(2)(2) For other toxic and organoleptic substances intentionally added to noncontact cooling water by the permittee, the department shall follow the procedures specified in ss. NR 106.05 and 106.06 to calculate a water quality based effluent limitation and determine whether the limitation is necessary in the permit. If there is no water quality criterion for an additive and there are potential water quality impacts from the additive, the department shall establish a secondary value for the additive in accordance with ch. NR 105 and calculate a limitation based on that value. All of the following requirements apply to the use and discharge of additives: NR 106.10(2)(a)(a) A permittee shall obtain written approval from the department prior to use of the additive. NR 106.10(2)(b)(b) A permittee shall provide the department with dosage information and safety data sheets and toxicological data, as requested by the department to meet minimum data requirements specified in ss. NR 105.05 (4) and 105.06 (6) for each additive for which approval is sought. NR 106.10(2)(c)(c) Prior to increasing the usage of an additive in amounts greater than authorized by the department, a permittee shall get written approval from the department for the increased usage. NR 106.10(2)(d)(d) After reissuance, if a permittee wants to use a new additive not previously approved by the department, the permittee shall get written approval from the department prior to use of the additive. NR 106.10(2)(e)(e) A permittee may only use additives in accordance with the conditions of the department approval and any applicable permit terms. If the department does not approve use of the additive, the additive may not be discharged. NR 106.10 HistoryHistory: Cr. Register, February, 1989, No. 398, eff. 3-1-89; am. (1) (a), (b) and (2), cr. (1) (d), August, 1997, No. 500, eff. 9-1-97; CR 03-050: am. (1) (intro.) Register February 2004 No. 578, eff. 3-1-04; CR 15-084: r. and recr. Register August 2016 No. 728, eff. 9-1-16; correction in (2) (intro.) made under s. 35.17, Stats., Register August 2016 No. 728. NR 106.11NR 106.11 Multiple discharges. Whenever the department determines that more than one discharge may be affecting the water quality of the same receiving water for one or more substances, the provisions of this chapter shall be used to calculate the combined allowable load from the discharges necessary to meet the water quality criteria for the substances. 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 section, 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 section. Permittees shall be given the opportunity to comment to the department on any determination made under this section. NR 106.11 NoteNote: The method of allocating the combined allowable load in s. NR 106.11 is not required to be based on the effluent flow rates specified in s. NR 106.06 (4) (d). NR 106.115NR 106.115 Additivity of dioxins and furans. The 2,3,7,8-TCDD toxicity equivalence concentration in effluent shall be used when developing waste load allocations and for purposes of establishing water quality based effluent limits. NR 106.115(1)(1) For the chlorinated dibenzo-p-dioxins (CDDs) listed in Tables 8 and 9 in ch. NR 105, the potential adverse additive effects of all dioxin (CDD) and chlorinated dibenzofuran (CDF) congeners in effluents shall be accounted for as specified in this section. NR 106.115(2)(2) The Toxicity Equivalency Factor (TEF) in Table 1 and Bioaccumulation Equivalency Factor (BEF) in Table 2 shall be used when calculating a 2,3,7,8-TCDD toxicity equivalence concentration in effluent to be used when implementing both human health noncancer and cancer criteria. The chemical concentration of each CDD and CDF in effluent shall be converted to a 2,3,7,8-TCDD toxicity equivalence concentration in effluent by using the following equation: (TEC)tcdd = S (C)x (TEF)x (BEF)x
where:
(TEC)tcdd = 2,3,7,8-TCDD toxicity equivalence
concentration in effluent
(C)x = concentration of total chemical x in effluent
(TEF)x = TCDD toxicity equivalency factor for x from table 1
(BEF)x = TCDD bioaccumulation equivalency factor for x from table 2
Table 1 — Toxicity Equivalency Factor for
CDDS and CDFs
Table 2 — Bioaccumulation Equivalency Factor
for CDDs and CDFs
NR 106.115 HistoryHistory: Cr. Register, August, 1997, No. 500, eff. 9-1-97; CR 03-050: renum. from NR 106.16 Register February 2004 No. 578, eff. 3-1-04; CR 09-123: am. (1) Register July 2010 No. 655, eff. 8-1-10; CR 15-085: am. Table 1 (title), Table 2 (title) Register August 2016 No. 728, eff. 9-1-16. NR 106.117(1)(a)3.3. “Recommencing discharger” means a permitted source that recommences discharge after terminating its operations. NR 106.117(1)(b)(b) The first permit issued by the department to a new source or a new discharger shall contain a schedule of compliance only when necessary to allow a reasonable opportunity to attain compliance with state or federal limitations promulgated after commencement of construction but less than 3 years before commencement of the discharge. NR 106.117 NoteNote: The department recognizes pollution control equipment start-up problems may arise at the commencement of a new discharge. Enforcement discretion may be used in the 90 days following commencement of discharge, in such cases.
NR 106.117(1)(c)(c) For recommencing dischargers, a schedule of compliance shall be included in the permit only when necessary to allow a reasonable opportunity to attain compliance with limitations promulgated less than 3 years before recommencement of the discharge. NR 106.117(2)(2) Schedules for reissued or modified permits. A reissued or modified permit may, when appropriate, include a schedule for compliance with new or more stringent effluent limitations that are established by this chapter. NR 106.117(3)(3) Schedule requirements. A schedule of compliance included in a permit shall meet all of the following conditions: NR 106.117(3)(a)(a) Time for compliance. Any schedule of compliance under this section shall require compliance as soon as possible but may not extend beyond any applicable federal or state statutory deadlines. The schedule also may not extend beyond 5 years from the date that the permit is reissued or modified to include the new or more stringent effluent limitation, except as provided in par. (b) or as provided in other chapters. NR 106.117(3)(b)(b) Great Lakes dischargers. For an existing discharger to the Great Lakes system with a permit that was originally issued before March 23, 1997, if the effluent limitation is based on a secondary value under s. NR 105.03 (25), the permit shall require compliance with the secondary value based limitation within a reasonable period of time, no later than 5 years after permit reissuance or modification to include the limitation. The compliance schedule may allow the permittee additional time to conduct studies for the purpose of revising the secondary value or to develop a criterion if requested by the permittee in accordance with s. NR 106.07 (8). The time period allowed for such studies may not exceed 2 years. In cases where the permittee wishes to conduct a study on the secondary value, the permit also shall contain a reopener clause, requiring a permit modification if the department determines the specified studies demonstrate that a revised limitation is appropriate. Any revised limitation shall be incorporated through a permit modification and a reasonable time period, up to 5 years, may be allowed for compliance, but in no case may the compliance schedule for the revised limitation extend beyond 7 years from the date the secondary value based limitation was initially included in the permit. NR 106.117(3)(c)(c) Interim dates. If a permit establishes a schedule of compliance that exceeds one year from the date of permit reissuance or modification, the schedule shall set forth interim requirements and the dates for their achievement as follows: NR 106.117(3)(c)1.1. The time between dates for the achievement of interim requirements may not exceed one year, except in the case of a schedule for compliance with standards for sewage sludge use and disposal, the time between dates for the achievement of interim requirements shall not exceed 6 months. NR 106.117(3)(c)2.2. If the time necessary for completion of any interim requirement is more than one year and is not readily divisible into stages for completion, the permit shall specify dates for the submission of reports of progress toward completion of the interim requirements and indicate a projected completion date. NR 106.117(3)(d)(d) Pollution and waste minimization measures. The schedule of compliance may require the permittee to evaluate pollution and waste minimization measures as a means for complying with the effluent limitation.
