Chapter NR 212

NR 212.73(3)(d)3. 3. If multiple EPA-approved TMDLs are prepared for impaired waters, and the TMDLs include allocations for the same pollutant for one or more of the same sources, then the applicable allocations that are protective of both immediate and downstream segments shall be used for TMDL implementation, including permitting.

NR 212.73(3)(d)4. 4. Pollutant degradation and transport may be considered when developing allocations.

NR 212.73(3)(d)5. 5. Natural background loads may be accounted for in a TMDL through an allocation to a single category or through individual allocations to applicable sources of natural background loads.

NR 212.73(3)(d)6. 6. Nonpoint sources may be accounted for in a TMDL through an allocation to a single category or through individual load allocations to various nonpoint sources.

NR 212.73(3)(d)7. 7. Point source dischargers covered through individual permits shall be assigned individual waste load allocations. Point source dischargers covered through general permits may be accounted for through an allocation to a single category or through individual wasteload allocations.

NR 212.73(3)(e) (e) TMDLs shall include a margin of safety sufficient to account for technical uncertainties in establishing the TMDL and shall describe the manner in which the margin of safety is determined and incorporated into the TMDL. The margin of safety may be provided explicitly by leaving a portion of the loading capacity unallocated, implicitly by using conservative modeling assumptions to establish wasteload allocations and load allocations, or a combination thereof. If a portion of the loading capacity is left unallocated to provide a margin of safety, the amount left unallocated shall be documented. If conservative modeling assumptions are relied on to provide a margin of safety, the specific assumptions providing the margin of safety shall be described.

NR 212.73(3)(f) (f) A portion of the TMDL may be allocated to a reserve capacity to account for new or increased discharges, or other sources not allocated in the TMDL. When such reserve allocations are not included in a TMDL, any increased loadings of the pollutant for which the TMDL was developed that are due to a new or expanded discharge may not be allowed unless the TMDL is revised to include an allocation for the new or expanded discharge or the new or expanded discharge is offset by a reduction of the pollutant in the watershed covered by the TMDL.

NR 212.73(4) (4) Monitoring data. Monitoring data shall be collected to support the development of the TMDL and track implementation of a TMDL. Monitoring data shall be used for all of the following:

NR 212.73(4)(a) (a) To demonstrate progress towards achieving water quality standards such as quantifying pollutant reductions made through implementation of the TMDL and evaluating the effectiveness of controls being used to implement the TMDL.

NR 212.73(4)(b) (b) To validate the assumptions and scientific analysis used to establish the TMDL or revise the TMDL, if necessary.

NR 212.73(5) (5) Reasonable assurance. A TMDL, implementation plan for a TMDL, or remediation plan shall provide reasonable assurances that water quality standards will be attained within a reasonable timeframe. Determining the reasonable period of time in which water quality standards will be met is a case-specific determination considering a number of factors including, but not limited to: receiving water characteristics including persistence, behavior, and ubiquity of pollutants of concern; the types of remedial activities necessary; and available regulatory and non-regulatory controls.

NR 212.73 History History: CR 15-085: cr. Register August 2016 No. 728, eff. 9-1-16.

NR 212.74 NR 212.74 Developing TMDLs for nearshore and open waters of the Great Lakes. This section describes requirements for deriving TMDLs for waters of the Great Lakes system as defined in s. NR 102.22 (5) and inland lakes within the Great Lakes system with no appreciable flow relative to their volumes. This section applies to TMDLs for all pollutants excluding the following: alkalinity, ammonia, bacteria, biochemical oxygen demand, chlorine, color, dissolved oxygen, dissolved solids, pH, phosphorus, salinity, temperature, total and suspended solids, turbidity, and whole effluent toxicity. In addition to the requirements specified in s. NR 212.73, TMDLs in this section shall also meet all of the following:

NR 212.74(1) (1) TMDLs shall reflect, when appropriate and when sufficient data are available, contributions to the water column from sediments inside and outside of any applicable mixing zones. TMDLs shall be sufficiently stringent so as to prevent accumulation of the pollutant of concern in sediments to levels injurious to designated or existing uses, human health, wildlife, and aquatic life.

NR 212.74(2) (2) TMDLs shall reflect, when appropriate and when sufficient data are available, discharges resulting from wet weather events.

NR 212.74(3) (3) TMDLs shall reflect, when appropriate and when sufficient data are available, background concentrations of pollutants stemming from atmospheric deposition, sediment release or resuspension, or as a result of chemical reactions.

NR 212.74 History History: CR 15-085: cr. Register August 2016 No. 728, eff. 9-1-16.

NR 212.75 NR 212.75 Developing TMDLs for Great Lakes systems tributaries and connecting channels. This section describes conditions for deriving TMDLs for tributaries and connecting channels of the Great Lakes system as defined in s. NR 102.12 (1) that exhibit appreciable flows relative to their volumes. This section applies to TMDLs for all pollutants excluding the following: alkalinity, ammonia, bacteria, biochemical oxygen demand, chlorine, color, dissolved oxygen, dissolved solids, pH, phosphorus, salinity, temperature, total and suspended solids, turbidity, and whole effluent toxicity. In addition to the requirements specified in s. NR 212.73, TMDLs in this section shall also meet all of the following:

NR 212.75(1) (1) TMDLs shall reflect, when appropriate and when sufficient data are available, contributions to the water column from sediments inside and outside of any applicable mixing zones. TMDLs shall be sufficiently stringent so as to prevent accumulation of the pollutant of concern in sediments to levels injurious to designated or existing uses, human health, wildlife, and aquatic life.

NR 212.75(2) (2) TMDLs shall reflect, when appropriate and when sufficient data are available, discharges resulting from wet weather events.

NR 212.75(3) (3) TMDLs shall reflect, when appropriate and when sufficient data are available, background concentrations of pollutants stemming from atmospheric deposition, sediment release or resuspension, or as a result of chemical reactions.

NR 212.75(4) (4) Design flows shall be used unless data exist to demonstrate that an alternative stream design flow is appropriate for stream-specific and pollutant-specific conditions. For purposes of calculating a TMDL, the stream design flows shall be all of the following:

NR 212.75(4)(a) (a) The 7-day, 10-year stream design flow (7Q10), or the 4-day, 3-year biologically-based stream design flow for chronic aquatic life criteria or values.

NR 212.75(4)(b) (b) The 1-day, 10-year stream design flow (1Q10), for acute aquatic life criteria or values.

NR 212.75(4)(c) (c) The harmonic mean flow for human health criteria or values.

NR 212.75(4)(d) (d) The 90-day, 10-year flow (90Q10) for wildlife criteria.

NR 212.75(4)(e) (e) TMDLs, calculated using dynamic modeling are not required to incorporate the stream design flows specified in pars. (a) to (d) of this procedure.

NR 212.75(5) (5) The loading capacity is initially calculated at the farthest downstream location for the impaired reach by multiplying the applicable criterion or target value by the flow condition described in sub. (4). The loading capacity is then compared to the loadings at sites within the basin to assure that applicable numeric criteria or values for a given pollutant are not exceeded at all applicable sites. The lowest load is then selected as the loading capacity to be consistent with the attainment of each applicable numeric criterion or value for a given pollutant.

NR 212.75 History History: CR 15-085: cr. Register August 2016 No. 728, eff. 9-1-16.

NR 212.76 NR 212.76 Establishing WQBELs for publicly and privately owned wastewater facilities or treatment works.

NR 212.76(1) (1) WQBEL calculation procedures. Calculation of WQBELs derived from TMDL wasteload allocations shall be derived consistent with the wasteload allocation and assumptions of an EPA-approved TMDL. The department shall use scientifically defensible methods to calculate these WQBELs. All of the following conditions shall apply when calculating WQBELs derived from TMDL wasteload allocations:

NR 212.76(1)(a) (a) WQBELs shall be expressed as mass limitations unless the pollutant cannot appropriately be expressed by mass or a mass limitation is infeasible because the mass of the pollutant cannot be related to a measure of operation.

NR 212.76(1)(b) (b) When establishing WQBELs in permits the department shall ensure that substances are not present in amounts that are acutely toxic to animals, plants, or aquatic life in all surface waters including those portions of the mixing zone normally habitable by aquatic life and effluent channels as required by s. NR 102.04 (1).

NR 212.76(1)(c) (c) When establishing WQBELs in permits the department shall ensure that substances are not exceeding applicable chronic toxicity criteria, wildlife criteria, taste and odor criteria, human threshold criteria, human cancer criteria, and secondary values, as specified in chs. NR 102 to 105, after dilution with an appropriate allowable quantity of receiving water flow unless the conditions specified in s. NR 102.05 (3) or the TMDL wasteload allocation require less dilution or no dilution be allowed. WQBELs may be more restrictive than the applicable water quality criteria in order to be consistent with the wasteload allocation and assumptions of an EPA-approved TMDL.

NR 212.76(2) (2) WQBEL calculation procedures in Great Lakes basin. In addition to the requirements in sub. (1), WQBELs derived from TMDLs under ss. NR 212.74 and 212.75 shall also meet all of the following:

NR 212.76(2)(a) (a) WQBELs shall be sufficiently stringent to ensure that accumulation of the pollutant of concern cannot occur in sediments at levels injurious to designated or existing uses, human health, wildlife, or aquatic life.

NR 212.76(2)(b) (b) When establishing WQBELs in permits the department shall assume that the pollutant of concern does not degrade over time unless any the following conditions are met:

NR 212.76(2)(b)1. 1. Scientifically valid field studies or other relevant information demonstrate that degradation of the pollutant is expected to occur under the full range of environmental conditions expected.

NR 212.76(2)(b)2. 2. Scientifically valid field studies or other relevant information address other factors that affect the level of pollutants in the water column including suspension of sediments, chemical speciation, and biological and chemical transformation.

NR 212.76(3) (3) Mixing zones for bioaccumulative chemicals of concern (BCCs). WQBELs derived from TMDL wasteload allocations for BCCs shall be consistent with and no less stringent than the mixing zone provisions under s. NR 106.06 (2).

NR 212.76(4) (4) Expression of limits. WQBELs derived from TMDL wasteload allocations shall be expressed consistent with the provisions specified in s. NR 205.065 unless impracticable or an alternative expression of limitations is determined appropriate by the department and is consistent with the assumptions of the TMDL.

NR 212.76(5) (5) Compliance schedules. When a permit is issued, reissued, or modified with new WQBELs based on a TMDL established using the procedures in this subchapter, the department may include a compliance schedule to achieve compliance with the TMDL based limitation if the permittee’s treatment system is unable to immediately comply with the limitation. The compliance schedule shall meet all of the following conditions:

NR 212.76(5)(a) (a) The schedule of compliance will lead to compliance with the water quality based effluent limitation as soon as possible.

NR 212.76(5)(b) (b) The compliance schedule may not extend beyond the expiration date of the permit unless extended compliance schedules are authorized in ch. NR 217, other Wisconsin administrative code chapters, or a TMDL schedule in an approved areawide water quality management plan under ch. NR 121. Compliance schedules for toxic and organoleptic substances shall be consistent with the requirements of s. NR 106.117.

NR 212.76(5)(c) (c) Dates between interim compliance steps in the compliance schedule may not exceed one year.

NR 212.76(5)(d) (d) Development and implementation of an optimization plan or pollution minimization plan may be included as part of the compliance schedule as a means of complying with the effluent limitation.

NR 212.76(6) (6) Relationship of WQBELS derived from TMDL wasteload allocations and other wqbels. The department may include WQBELs derived from TMDL wasteload allocations in a permit in addition to, or in lieu of, other WQBELs.

NR 212.76 History History: CR 15-085: cr. Register August 2016 No. 728, eff. 9-1-16.

NR 212.77 NR 212.77 Public Participation.

NR 212.77(1) (1) The department shall conduct an informational public hearing and provide an opportunity for the public to comment on a proposed TMDL before the TMDL is submitted to EPA for approval. The minimum time period for written comments shall be 30 days from the date of public notice of a TMDL. The department shall post notice of a proposed TMDL on the department’s website.

NR 212.77(2) (2) Once a TMDL is approved by EPA, the TMDL is automatically incorporated into all applicable areawide water quality management plans, lake management plans, or remedial action plans.

NR 212.77(3) (3) The department may not impose a WQBEL based on a TMDL in a permit under s. NR 212.76 (6), until the TMDL has been approved by EPA.

NR 212.77(4) (4) The department shall provide public notice and provide an opportunity for comment on a calculated WQBEL that is derived from the EPA-approved TMDL during the public notice and comment period on the permit as provided in ch. NR 203 and ch. 283, Stats.

NR 212.77 History History: CR 15-085: cr. Register August 2016 No. 728, eff. 9-1-16.