Chapter NR 106

NR 106.145(7)(e)10. 10. Any other relevant information.

NR 106.145(7)(f) (f) The pollutant minimization program plan shall include all of the following:

NR 106.145(7)(f)1. 1. Identify specific activities to be undertaken and a relative timeline to implement those activities.

NR 106.145(7)(f)2. 2. State which, if any, activities have already been implemented and how effective they were in reducing potential and actual mercury discharges.

NR 106.145(7)(f)3. 3. Commit the permittee to document how the pollutant minimization program plan was implemented including measures such as the number of contacts of various types made, programs implemented and other activities.

NR 106.145(7)(f)4. 4. Provide for steps to measure the effectiveness of the pollution minimization program elements in reducing potential and actual mercury discharges. Where the permittee regularly monitors influent, effluent, sludge or biosolids for mercury, measures shall include any changes in mercury concentrations over comparable historic data. Where practicable, other measures or estimates of mercury reductions from programs such as mercury recycling, collection or disposal may also be included.

NR 106.145(7)(g) (g) Within 12 months of the beginning of implementation of the pollutant minimization program and annually thereafter, the permittee shall report to the department on the progress of the pollutant minimization program as required in s. NR 106.04 (5). This annual report shall include all of the following:

NR 106.145(7)(g)1. 1. An evaluation of the effectiveness of the program in accordance with the plan.

NR 106.145(7)(g)2. 2. Identification of barriers that have limited program effectiveness and adjustments to the program that will be implemented during the next year to help address these barriers.

NR 106.145(7)(h) (h) Permittees may collaborate with one another or other parties to plan and implement a pollutant minimization program.

NR 106.145 Note Note: Permittees that do not prepare or effectively implement a pollutant minimization program are subject to regulatory requirements for mercury, without alternative mercury effluent limitations to water quality standards. For municipal permittees this may mean development and enforcement of mercury discharge standards for users of the public sewerage system pursuant to s. NR 211.10 (3). For users of the municipal sewerage system this may mean changes in processes, installation of treatment technology, or other means to comply with the municipal mercury discharge standards pursuant to s. NR 211.10 (1). Implementation of the municipal mercury discharge standards may require a program of user discharge permits and wastewater discharge monitoring.

NR 106.145(8) (8) Alternative mercury effluent limitation applications.

NR 106.145(8)(a) (a) To apply for an alternative mercury effluent limitation under this section, a permittee shall do all of the following:

NR 106.145(8)(a)1. 1. Submit an alternative mercury effluent limitation application at the same time as the application for permit reissuance following data generation.

NR 106.145(8)(a)2. 2. State the basis for concluding that wastewater treatment technology for mercury is impractical.

NR 106.145(8)(a)3. 3. Supply representative effluent monitoring results of sufficient number and analytical sensitivity to quantify with reasonable certainty the concentration and mass of mercury discharged. Representative sample results shall meet all of the following requirements:

NR 106.145(8)(a)3.a. a. Be of sufficient quantity to allow calculation of the upper 99th percentile values pursuant to s. NR 106.05 (5).

NR 106.145(8)(a)3.b. b. Reasonably represent current conditions.

NR 106.145(8)(a)3.c. c. Meet the data quality requirements of subs. (9) and (10).

NR 106.145(8)(a)3.d. d. Represent a time period of at least 2 years.

NR 106.145(8)(a)4. 4. Submit a pollution minimization program plan described in sub. (7) (f).

NR 106.145(8)(b) (b) A permittee applying for renewal of an alternative mercury effluent limitation previously granted shall follow the procedures in par. (a) except for all of the following:

NR 106.145(8)(b)1. 1. The permittee shall submit information indicating whether the permittee substantially complied with mercury regulation conditions of the existing permit.

NR 106.145(8)(b)2. 2. A new pollutant minimization program plan shall re-evaluate the plan required under the previous permit.

NR 106.145(9) (9) Sampling requirements.

NR 106.145(9)(a) (a) Sample types may be grab or 24-hour composite. “Grab sample” and “24-hour composite sample” have the meanings specified in s. NR 218.04.

NR 106.145(9)(b) (b) Sample collection methods shall be consistent with EPA Method 1669: Sampling Ambient Water for Trace Metals at EPA Water Quality Criteria Levels, EPA-821-R-96-011.

NR 106.145(9)(c) (c) Requirements for field blanks are as follows. A field blank means an aliquot of mercury-free reagent water that is placed in a sample container, shipped to the field and treated as a sample in all respects, including contact with the sampling devices and exposure to sampling site conditions, filtration, storage, preservation, and all analytical procedures. The purpose of the field blank is to determine whether the field or sample transporting procedures and environments have contaminated the sample:

NR 106.145(9)(c)1. 1. At least one field blank shall be collected at each site for each day a sample is collected. If more than one sample is collected in a day, at least one field blank for each 10 samples collected on that day shall be collected.

NR 106.145(9)(c)2. 2. If mercury or any potentially interfering substance is found in the field blank at a concentration equal to or greater than 0.5 ng/L, the limit of detection or one-fifth the level in the associated sample, whichever is greater, results for associated samples may not be used for regulatory compliance purposes unless the conditions in subd. 3. are met.

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 Note Note: 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 Note Note: When using the data, the department may subtract field blanks from sample concentrations on a case-by-case basis.

NR 106.145(10) (10) Laboratory analysis requirements.

NR 106.145(10)(a) (a) In this subsection, “method blank” and “limit of detection” have the meanings specified in s. NR 149.03.

NR 106.145 Note Note: “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 History History: 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 106.15 NR 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 History History: Cr. Register, February, 1989, No. 398, eff. 3-1-89.

subch. IV of ch. NR 106 Subchapter IV — Effluent Limitations for Ammonia Discharges

NR 106.30 NR 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 Note Note: Any discharges of ammonia from a concentrated animal feeding operation (CAFO) are regulated under ch. NR 243.

NR 106.30 History History: CR 03-050: cr. Register February 2004 No. 578, eff. 3-1-04.

NR 106.31 NR 106.31 Definitions. In this subchapter:

NR 106.31(1) (1) “Acute criterion” or “ATC” has the meaning in s. NR 105.03 (2)

NR 106.31(2) (2) “Chronic criterion” or “CTC” has the meaning in s. NR 105.03 (15)

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 History History: CR 03-050: cr. Register February 2004 No. 578, eff. 3-1-04.

NR 106.32 NR 106.32 Calculation of water quality-based effluent limitations for ammonia.

NR 106.32(1) (1) Basis for limitations.

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) (2) Limitations based on acute toxicity.

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 Note Note: 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.