Chapter NR 106

NR 106.90(4)(c)1. 1. Evaluate the feasibility of achieving greater salt efficiencies, greater than 3350 grains of hardness exchange per pound of salt.

NR 106.90(4)(c)2. 2. Evaluate softening alternatives that replace the sodium cycle ion exchange method of softening.

NR 106.90(4)(c)3. 3. Blend softened and unsoftened water to strike a balance between delivered water quality and environmental protection.

NR 106.90(4)(d) (d) For dairies:

NR 106.90(4)(d)1. 1. For plants that make brine salted cheeses, evaluate the feasibility of membrane filtration for reconditioning the brine so that it can be reused.

NR 106.90(4)(d)2. 2. For plants that make brine salted cheeses, evaluate the feasibility of using a no-brine make procedure in which salt is added directly to curd during the manufacturing procedure, thereby reducing salt discharges from spent brines.

NR 106.90(4)(e) (e) For those facilities which process vegetables:

NR 106.90(4)(e)1. 1. Evaluate the feasibility of eliminating brine flotation for quality grading, if applicable.

NR 106.90(4)(e)2. 2. Evaluate the feasibility of installing a closed-loop system for cooling water.

NR 106.90(4)(e)3. 3. Evaluate the feasibility of installing a brine recovery and reuse system for reducing salt waste at the point of supplying flavorings to containers.

NR 106.90(4)(f) (f) For those facilities which process meats:

NR 106.90(4)(f)1. 1. Investigate the feasibility of replacing brine chills with air, water or air-water chills.

NR 106.90(4)(f)2. 2. Reduce drainback through operational and equipment improvements.

NR 106.90(4)(f)3. 3. Investigate the feasibility of chill brine reconditioning and reuse.

NR 106.90(4)(f)4. 4. Evaluate the feasibility of reusing once-through cooling water, or installing a closed-loop cooling water system.

NR 106.90(4)(f)5. 5. Evaluate phosphonate additives instead of softened water.

NR 106.90(4)(g) (g) For any other facility not listed in pars. (a) to (f), evaluate the feasibility of replacing or upgrading equipment and processes, and the use of alternative softening technologies to affect chloride reductions.

NR 106.90(5) (5) Source reduction reporting. Following the completion of tier 1, 2 or 3 source reduction activities specified in the permit, but no later than 6 months prior to permit expiration, the permittee shall file a written report to the department documenting the current reduction as well as the anticipated future reduction in salt usage and chloride effluent concentrations.

NR 106.90 History History: Cr. Register, January, 2000, No. 529, eff. 2-1-00.

NR 106.91 NR 106.91 Variances for POTWs which accept wastewater from public water systems treating water to meet primary safe drinking water act standards. Publicly owned treatment works that accept wastewater from a public water system treating water to meet the primary maximum contaminant levels specified in ch. NR 809, if not able to meet the calculated limitation, may apply to the department for a variance from the water quality standard used to derive the limitation following the procedure specified in this subchapter. The department shall seek U.S. environmental protection agency approval before a variance is included in a permit. Upon approval, the permittee may be given an interim limitation, a target value, a target limitation and appropriate source reduction requirements, under s. NR 106.83 in the permit upon permit reissuance or modification. No calculated limitation, interim limitation, target value, target limitation, or source reduction requirement shall interfere with the attainment of the primary maximum contaminant levels specified in ch. NR 809.

NR 106.91 History History: Cr. Register, January, 2000, No. 529, eff. 2-1-00; CR 15-085: am. Register August 2016 No. 728, eff. 9-1-16.

NR 106.92 NR 106.92 Authority of a publicly owned treatment works to regulate chloride discharges. A publicly owned treatment works has the authority to regulate the discharge of chloride as enumerated in s. NR 211.40.

NR 106.92 History History: Cr. Register, January, 2000, No. 529, eff. 2-1-00.

NR 106.93 NR 106.93 New discharges. Any point source which has not been authorized under a WPDES permit prior to February 1, 2000, shall be required to meet the calculated limitations. Relocation of an existing discharge which was issued a WPDES permit prior to February 1, 2000, may not be considered a new discharge.

NR 106.93 History History: Cr. Register, January, 2000, No. 529, eff. 2-1-00.

NR 106.94 NR 106.94 Relocation of an existing discharge. An existing discharge which was issued a WPDES permit prior to February 1, 2000, and which is relocated after February 1, 2000, may be subject to voluntary source reduction activities and both an interim limitation and a target value or an interim limitation and a target limitation pursuant to s. NR 106.83 if the provisions of ch. NR 207 are met. Relocation includes the diversion of a discharge from a land treatment system to a surface water.

NR 106.94 History History: Cr. Register, January, 2000, No. 529, eff. 2-1-00.

NR 106.95 NR 106.95 Multiple discharges. The provisions of s. NR 106.11 are applicable to multiple discharges of chloride.

NR 106.95 History History: Cr. Register, January, 2000, No. 529, eff. 2-1-00.

NR 106.96 NR 106.96 Analytical methods and laboratory requirements. The provisions of s. NR 106.14 regarding analytical methods, sample handling and laboratory requirements are applicable to discharges of chloride.

NR 106.96 History History: Cr. Register, January, 2000, No. 529, eff. 2-1-00.

subch. VIII of ch. NR 106 Subchapter VIII — Permit Requirements for PFOS and PFOA Discharges

NR 106.97 NR 106.97 Purpose. The purpose of this subchapter is to specify how the department will regulate the discharge of PFOS and PFOA in wastewater to surface waters of the state that are subject to the PFOS and PFOA standards under s. NR 102.04 (8) (d) 1. pursuant to the permitting program under ch. 283, Stats.

NR 106.97 History History: CR 21-083: cr. Register July 2022 No. 799, eff. 8-1-22.

NR 106.975 NR 106.975 Definitions. In this subchapter:

NR 106.975(1) (1) “Composite sample” has the meaning specified in s. NR 218.04 (11).

NR 106.975(2) (2) “Equipment blank” means a sample collected by passing laboratory-verified PFAS-free water over or through field sampling equipment before the collection of field samples to evaluate potential contamination from the equipment used during sampling.

NR 106.975(3) (3) “Grab sample” has the meaning specified in s. NR 218.04 (10).

NR 106.975(4) (4) “Major municipal discharger” means a treatment works or system that has a major municipal discharge as defined in s. NR 200.02 (7).

NR 106.975(5) (5) “Minor municipal discharger” means a treatment works or system that has a minor municipal discharge as defined in s. NR 200.02 (8).

NR 106.975(6) (6) “Municipal discharger” means all publicly operated treatment works and privately owned domestic sewage treatment works subject to the requirements under ch. NR 210.

NR 106.975(7) (7) “New discharger” means any building, structure, facility, or installation from which there is or may be a discharge of pollutants, that is not a new source, and that did not commence the discharge of pollutants at a particular site prior to August 1, 2022, and which has never received a finally effective WPDES permit for discharges at that site.

NR 106.975(8) (8) “New source” has the meaning specified in s. NR 106.117.

NR 106.975(9) (9) “PFAS” means a perfluoroalkyl or polyfluoroalkyl substance that contains a straight or branching chain of carbon atoms in which one or more of the carbon atoms have fluorine atoms attached at all bonding sites not occupied by another carbon atom and the fluorinated part of the molecule can be expressed as CnF2n+1.

NR 106.975(10) (10) “Perfluorooctanoic acid” or “PFOA” has the meaning specified in s. NR 102.03 (4e).

NR 106.975(11) (11) “Perfluorooctane sulfonate” or “PFOS” has the meaning specified in s. NR 102.03 (4m).

NR 106.975(12) (12) “Primary industry” has the meaning specified in s. NR 200.02 (15).

NR 106.975(13) (13) “Secondary industry” has the meaning specified in s. NR 200.02 (17).

NR 106.975(14) (14) “Source reduction activities” means structural or non-structural measures, practices, techniques, activities, or devices employed to reduce or eliminate the transfer of PFOS and PFOA from sources into surface waters of the state.

NR 106.975(15) (15) “Treatment works” has the meaning specified in s. 283.01 (18), Stats.

NR 106.975(16) (16) “WPDES permit” means the Wisconsin pollutant discharge elimination system permit issued by the department under ch. 283, Stats., for the discharge of pollutants.

NR 106.975 History History: CR 21-083: cr. Register July 2022 No. 799, eff. 8-1-22.

NR 106.98 NR 106.98 Determination of the necessity for reducing PFOS and PFOA in discharges.

NR 106.98(1) (1) General. This section establishes the procedures for determining when a permitted discharge has the reasonable potential to cause or contribute to an exceedance of the PFOS or PFOA standards under s. NR 102.04 (8) (d) 1.

NR 106.98(2) (2) Data generation. At the first reissuance of a WPDES permit after August 1, 2022, the department shall require in the reissued permit that the permittee monitor and report PFOS and PFOA at the frequencies and locations specified under this subsection, for up to 2 years, except if a waiver has been granted or reduced frequency is approved under sub. (3). All samples shall be collected and analyzed consistent with the requirements under ch. NR 219 and s. NR 106.995. The following sample frequencies apply to each category of permitted dischargers:

NR 106.98(2)(a) (a) For a major municipal discharger with an average flow rate greater than or equal to 5 million gallons per day, the permittee shall, at a minimum, sample its effluent on a monthly basis. Influent monitoring will be determined on a case-by-case basis and shall be conducted at a frequency specified in the permit.

NR 106.98(2)(b) (b) For a major municipal discharger with an average flow rate greater than or equal to one million gallons per day but less than 5 million gallons per day, the permittee shall, at a minimum, sample its effluent once every 2 months. Influent monitoring will be determined on a case-by-case basis and shall be conducted at a frequency specified in the permit.

NR 106.98(2)(c) (c) For all other municipal dischargers, the permittee may only be required to sample for PFOS or PFOA if the department determines that PFOS or PFOA may be present in the discharge. In making this determination, the department shall consider the presence of potential PFOS or PFOA industrial wastes to the treatment works, the presence of nearby PFOS or PFOA remediation sites, and the presence of other potential sources of PFOS or PFOA that may contribute to any part of the minor municipal discharger. If the department determines that PFOA or PFOS may be present in the discharge, the department shall require that the permittee sample its influent and effluent at a frequency specified in the permit.

NR 106.98(2)(d) (d) For a primary or secondary industrial discharger, if the department determines that the permittee’s effluent may contain PFOS or PFOA, the department shall require that the permittee sample its effluent at least monthly.

NR 106.98(2)(e) (e) The department may require PFOS or PFOA monitoring for other discharges not included in one of the categories specified under pars. (a) to (d) if the department has a reasonable expectation that the discharge contains PFOS or PFOA at levels that will likely cause or contribute to an exceedance of the criteria under s. NR 102.04 (8) (d) 1.

NR 106.98 Note Note: The department has authority to sample the effluent from permitted facilities under s. 283.55, Stats.

NR 106.98 Note Note: The department has authority under s. NR 205.066 (1) to specify monitoring frequency for PFOS and PFOA in WPDES permits at its discretion on a case-by-case basis after 24 months.

NR 106.98(3) (3) Reduced sample frequency and waiver.

NR 106.98(3)(a) (a) The department may reduce monitoring frequency to once every 3 months for dischargers described under sub. (2) (a), (b) or (d) on a case-by-case basis, but only after at least 12 representative results have been generated.

NR 106.98(3)(b) (b) The department may waive the requirement to conduct PFOS or PFOA sampling for a discharger under sub. (2) if the department determines that it is unlikely that the permittee’s effluent will contain PFOS or PFOA at levels above the criteria in s. NR 102.04 (8) (d) 1. Any approved waivers shall be reviewed at each permit reissuance to determine whether any changes were made at the permitted facility or when the department becomes aware of new information that may result in new or increased discharges of PFOS or PFOA, in which case monitoring may be required.

NR 106.98(4) (4) Determination of the need for a PFOS and PFOA minimization plan. The department shall require creation and implementation of a PFOS and PFOA minimization plan that meets the requirements under s. NR 106.99 as a condition of a WPDES permit whenever the department determines that the discharge from the permitted facility contains PFOS or PFOA at concentrations that have reasonable potential to cause or contribute to an exceedance of the PFOS or PFOA standard in s. NR 102.04 (8) (d) 1. When determining whether a permitted discharge has the reasonable potential to cause or contribute to an exceedance of the PFOS or PFOA standard in s. NR 102.04 (8) (d) 1., the department shall use the methods in this subsection to make the determination and shall use representative data that meet the sampling and analysis requirements under ch. NR 219 and s. NR 106.995. When making a reasonable potential determination for a permitted discharge of PFOS or PFOA under this subsection, the department shall consider whether the intake provisions in s. NR 106.06 (6) (b) apply to the discharge. When calculating a water quality based effluent limitation for PFOS in the reasonable potential determination, the department shall apply the requirements in s. NR 106.06 (1) and (6) in the calculation and shall use the applicable PFOS criterion in s. NR 102.04 (8) (d) 1. A mixing zone under s. NR 106.06 (2) may not be included in the limit calculation for a discharge of PFOS. When calculating a water quality based effluent limitation for PFOA in the reasonable potential determination, the department shall apply the requirements in s. NR 106.06 (1) and (4) to (11) in the calculation and shall use the applicable PFOA criterion in s. NR 102.04 (8) (d) 1. If any one of the following methods indicate that there is reasonable potential for an exceedance of either the PFOS or PFOA standard, a PFOS and PFOA minimization plan shall be required in the permit:

NR 106.98(4)(a) (a) If at least 11 daily discharge concentrations of the substance are greater than the limit of detection, a PFOS and PFOA minimization plan is required for a permitted facility if the upper 99th percentile of the 30-day average discharge concentrations for PFOS or PFOA exceeds the applicable water quality based effluent limitation calculated under this subsection. To calculate upper 99th percentile values of the daily discharge concentrations, one of the following shall be used:

NR 106.98(4)(a)1. 1. If a log normal probability distribution is determined to be appropriate, the upper 99th percentile of the 30-day average discharge concentrations may be calculated using the equation under s. NR 106.05 (5) (a).

NR 106.98(4)(a)2. 2. If a probability distribution other than log normal is determined to be more appropriate and alternate methods are available, those methods may be used to calculate the upper 99th percentile.

NR 106.98(4)(b) (b) If fewer than 11 daily discharge concentrations of the substance are greater than the limit of detection, a PFOS and PFOA minimization plan is required for a permitted facility if the arithmetic average discharge concentration exceeds one-fifth of the applicable water quality based effluent limitation calculated under this subsection. The arithmetic average discharge concentration shall be calculated using all available representative discharge data, applying the following principles:

NR 106.98(4)(b)1. 1. If, in the judgment of the department, the analytical methods used to test for the substance represent acceptable methods, all values reported as less than the limit of detection shall be set equal to zero for calculation of the average concentration.

NR 106.98(4)(b)2. 2. If, in the judgment of the department, the analytical methods used to test for the substance do not represent the best acceptable methods, all values reported as less than the limit of detection shall be discarded from the data.

NR 106.98 History History: CR 21-083: cr. Register July 2022 No. 799, eff. 8-1-22.

NR 106.985 NR 106.985 PFOS and PFOA minimization plans, permit implementation procedures schedule.

NR 106.985(1) (1) General. If the department determines a permittee has reasonable potential to cause or contribute to an exceedance of the PFOS or PFOA standard in s. NR 102.04 (8) (d) 1. based on the reasonable potential procedures and data collected under s. NR 106.98, the department shall notify the permittee in writing that a PFOS and PFOA minimization plan that satisfies the requirements in s. NR 106.99 is required.

NR 106.985 Note Note: The department intends to make the reasonable potential determination during the term of the first reissued permit under s. NR 106.98 (2) as soon as the effluent sampling is completed. If the department determines that a permittee has reasonable potential to cause or contribute to an exceedance of the PFOS or PFOA standard, the department will modify the permit pursuant to the public notice and public participation procedures under ch. 283, Stats., and ch. NR 203 to incorporate the PFOS and PFOA minimization plan and other related terms and conditions, including annual progress reporting requirements and a schedule of compliance to meet applicable water quality based effluent limitations into the permit.

NR 106.985(2) (2) Schedules. The following timeline applies to a permittee that receives written notification that a PFOS and PFOA minimization plan is required under sub. (1):

NR 106.985(2)(a) (a) The permittee shall submit an initial PFOS and PFOA minimization plan that contains applicable goals and actions listed in s. NR 106.99 for department review and approval no later than 90 days after written notification under sub. (1) was sent from the department. The department may approve, conditionally approve, or reject the plan. The department shall provide a written response to the permittee within 120 days of receiving the plan and, if the initial plan is rejected, the response shall explain the reasons for the rejection. The permittee shall submit a revised plan that addresses all deficiencies and concerns within 30 days of department notification.

NR 106.985(2)(b) (b) As soon as possible after department approval of the PFOS and PFOA minimization plan, the department shall modify or revoke and reissue the permit in accordance with the public notice and public participation procedures required under ch. 283, Stats., and ch. NR 203 to include the PFOS and PFOA minimization plan and other related terms and conditions, including annual progress reporting requirements and a schedule of compliance to meet applicable water quality based effluent limitations. After the permit has been modified or revoked and reissued the permittee shall implement actions identified in the approved plan and report annually to the department on the progress of the PFOS and PFOA minimization plan. The annual PFOS and PFOA minimization plan report shall include all of the following:

NR 106.985(2)(b)1. 1. An analysis of trends in total effluent concentrations based on sampling, and for municipal dischargers an analysis of how influent and effluent concentrations vary with time and with significant loading of PFOS and PFOA.

NR 106.985(2)(b)2. 2. A summary of activities that have been implemented during the previous year and description of which, if any, activities from the approved PFOS and PFOA minimization plan were not pursued and why.

NR 106.985(2)(b)3. 3. An assessment of whether each implemented PFOS and PFOA minimization action appears to be effective or ineffective at reducing pollutant discharge concentrations and identification of actions planned for the upcoming year.

NR 106.985(2)(b)4. 4. Identification of barriers that have limited the plan’s effectiveness and adjustments to the plan that will be implemented during the next year to help address these barriers.

NR 106.985(2)(c) (c) A permittee may be allowed up to a maximum period of 85 months from the date the permit was modified or revoked and reissued to include the initial PFOS and PFOA minimization plan to implement PFOS and PFOA source reduction activities. After the initial PFOS and PFOA minimization plan is incorporated into the permit under par. (b), prior to each subsequent permit reissuance within the maximum 85 month period, the department shall evaluate whether levels of PFOS or PFOA in the effluent still have the reasonable potential to cause or contribute to an exceedance of the standard pursuant to s. NR 106.98 (4). If the department determines that levels of PFOS or PFOA in the effluent no longer have the reasonable potential to cause or contribute to an exceedance of the standard, the department may remove future PFOS and PFOA minimization plan requirements and future scheduled actions. However, the department shall include terms and conditions in the permit in accordance with the requirements in sub. (3). If the department determines that levels of PFOS or PFOA in the effluent still have the reasonable potential to cause or contribute to an exceedance of the PFOS or PFOA standard and there are feasible effective PFOS or PFOA source reduction activities that the permittee can still implement, the department may include the PFOS and PFOA minimization plan with source reduction activities in the reissued permit as a condition of the schedule. The department may require submittal of an updated PFOS and PFOA minimization plan as part of the reissuance application, or the permittee may choose to submit a revised PFOS and PFOA minimization plan. All revised PFOS and PFOA minimization plans are subject to department review and approval. If, however, the department or the permittee determine that there are no more feasible effective PFOS or PFOA source reduction activities that a permittee can implement, then the source reduction activities have been completed and par. (d) applies.

NR 106.985(2)(d) (d) After the actions in pars. (a) to (c) have been completed, all of the following requirements apply:

NR 106.985(2)(d)1. 1. For PFOS, after a permittee has completed all feasible PFOS source reduction activities within the maximum allowable period of 85 months, if the department determines levels of PFOS in the permitted discharge still have the reasonable potential, as determined using the procedures in s. NR 106.98 (4), to cause or contribute to an exceedance of the PFOS standard in s. NR 102.04 (8) (d) 1., the permittee shall be required to achieve compliance with a water quality-based effluent limitation that is calculated using the procedure in s. NR 106.98 (4). The limit shall be expressed as a monthly average and in accordance with the requirements in s. NR 106.07 unless impracticable.

NR 106.985(2)(d)2. 2. For PFOA, after a permittee has completed all feasible PFOA source reduction activities within the maximum allowable period of 85 months, if the department determines levels of PFOA in the discharge still have the reasonable potential, as determined under the procedures in s. NR 106.98 (4), to cause or contribute to an exceedance of the PFOA standard in s. NR 102.04 (8) (d) 1., a water quality-based effluent limitation for PFOA shall be included in the permit. The limitation shall be calculated using the calculation procedures in s. NR 106.98 (4). The PFOA limitation shall be expressed as a monthly average and in accordance with the requirements in s. NR 106.07 unless impracticable.

NR 106.985(2)(d)3. 3. The department may provide additional time in the compliance schedule consistent with the requirements under s. NR 106.117 to achieve compliance with the water quality-based effluent limitations as soon as reasonably possible.

NR 106.985(2)(d)4. 4. The department shall require continued monitoring of PFOS and PFOA with the water quality-based effluent limitation at a frequency specified in the permit and may require continued monitoring in the permit even if a water quality-based effluent limit for PFOS or PFOA is not required in the permit under this subsection.