Chapter NR 207

NR 207.12(1)(b) (b) The less stringent limitation complies with state water quality standards, including the antidegradation requirements in subch. I.

NR 207.12 Note Note: The requirements in sub. (1) is commonly referred to as the “safety clause” provision of the antibacksliding requirements in the Clean Water Act, and these requirements apply to any relaxation of any limitation. See 33 USC 1342(o)(3).

NR 207.12(2) (2) Relaxing a best professional judgment limitation. Best professional judgment limitations established under s. NR 220.21 (1) that have taken effect in a permit may be made less stringent in a reissued, revoked and reissued, or modified permit if the requirements of sub. (1) (a) and (b) are satisfied and one or more of the following apply:

NR 207.12(2)(a) (a) Material and substantial alterations or additions to the permitted facility occurred after the best professional judgment limitation was initially imposed in the permit, which justify the application of a less stringent effluent limitation,

NR 207.12(2)(b) (b) New information is available that was not available at the time of permit issuance and that would have justified the application of a less stringent effluent limitation at the time of permit issuance. New information under this paragraph does not include revised regulations, guidance, or test methods.

NR 207.12(2)(c) (c) The department determines that technical mistakes or mistaken interpretations of law were made when the best professional judgment limitation was initially imposed in the permit.

NR 207.12(2)(d) (d) A less stringent effluent limitation is necessary because of events over which the permittee has no control and for which there is no reasonably available remedy.

NR 207.12(2)(e) (e) The permittee has received department approval for any of the following:

NR 207.12(2)(e)1. 1. A modified technology based limitation under s. 283.13 (3), Stats.

NR 207.12(2)(e)2. 2. An extended compliance schedule under s. 283.13 (6), Stats.

NR 207.12(2)(e)3. 3. A modified technology based limitation under a fundamentally different factors variance under ss. NR 220.30 to 220.33.

NR 207.12(2)(e)4. 4. An alternative thermal effluent limitation under s. 283.17 (1), Stats.

NR 207.12(2)(f) (f) The permittee has installed the treatment facilities required to meet the effluent limitations in the previous permit and has properly operated and maintained the facilities, but has nevertheless been unable to achieve the best professional judgment limitations. In such a case, the effluent limitation in the reissued, revoked and reissued, or modified permit may be relaxed to reflect the level of pollutant control actually achieved. However, in no case may the limitation be less stringent than applicable effluent guidelines in effect at the time of reissuance or modification.

NR 207.12 Note Note: Subsection (2) is based on the requirement in 33 USC 1342(o)(1).

NR 207.12(3) (3) Relaxing a water quality based limitation or a limitation based on a state technology based treatment standard.

NR 207.12(3)(a) (a) General. Any effective water quality based effluent limitations, including those based upon a total maximum daily load or other wasteload allocation, or a limitation based on a state technology based treatment standard may be relaxed in a reissued, revoked and reissued, or modified permit if the requirements of sub. (1) (a) and (b) are met and, for an increased water quality based effluent limitation, one of the following requirements is satisfied:

NR 207.12(3)(a)1. 1. ‘Impaired waters and TMDL based limitations.’ For discharges of a pollutant to a receiving water or downstream water that is listed as an impaired water for the pollutant, any water quality based effluent limitation that is based upon a federally approved total maximum daily load for the pollutant may be made less stringent, provided at least one of the following applies:

NR 207.12(3)(a)1.a. a. Other wasteload allocated limitations for one or more dischargers to the impaired receiving water or downstream water are also adjusted so, cumulatively, the total maximum daily load allocations will still assure the attainment of water quality standards.

NR 207.12(3)(a)1.b. b. The designated use that is not being attained has been removed or revised in accordance with state regulatory procedures and approved by the EPA.

NR 207.12(3)(a)2. 2. ‘Impaired water and no federally approved TMDL developed.’ For discharges of a pollutant to a receiving water or downstream water that is listed as an impaired water for the pollutant but where a total maximum daily load has not yet been developed and approved by EPA for the pollutant, a water quality based effluent limitation for the pollutant may be made less stringent, provided at least one of the following applies:

NR 207.12(3)(a)2.a. a. The discharger can demonstrate that the increase in loading will be offset through a water quality trade or other means with another discharge of the same pollutant to the impaired water. The offset must be approved by the department and must be implemented prior to discharge.

NR 207.12(3)(a)2.b. b. The designated use that is not being attained has been removed or revised in accordance with state regulatory procedures and approved by the EPA, and the resulting less stringent limit would be subject to this paragraph.

NR 207.12(3)(a)3. 3. ‘Other waters that attain the water quality standard.’ For discharges of a pollutant to a surface water where neither the immediate receiving water or downstream water is an impaired water for the pollutant, any water quality based effluent limit, including a limitation based upon a total maximum daily load or other wasteload allocation, may be made less stringent provided water quality standards, including designated uses and antidegradation, are met.

NR 207.12 Note Note: The requirements in sub. (3) (a) 1. and 3. are based on the provisions of 33 USC 1313(d)(4) and still require compliance with sub. (1), which requires antidegradation requirements be satisfied. An example of the allowance for backsliding under this subdivision is a situation where the initial water quality based effluent limit was based on protection of a receiving water or a downstream water that did not meet the applicable water quality standard and the previously impaired water has now met or exceeded the water quality standard.

NR 207.12(3)(b) (b) Specific exceptions to backsliding prohibition. Any effective water quality based effluent limitations, including those based upon a total maximum daily load or other wasteload allocation, or a limitation based on a state technology based treatment standard may be relaxed in a reissued, revoked and reissued, or modified permit if sub. (1) (a) and (b) are satisfied and at least one of the following applies:

NR 207.12(3)(b)1. 1. Material and substantial alterations or additions to the permitted facility occurred after the limitation was initially imposed in the permit that justify the application of a less stringent effluent limitation.

NR 207.12(3)(b)2. 2. New information is available that was not available at the time of permit issuance and that would have justified the application of a less stringent effluent limitation at the time of permit issuance. New information under this subdivision includes the establishment of an EPA approved total maximum daily load for the pollutant and receiving water. New information under this subdivision does not include revised regulations, guidance, or test methods. The relaxation of a water quality based effluent limitation under this subdivision that is based upon a revised wasteload allocation, a revised TMDL, or any alternative grounds for translating water quality standards into effluent limitations, is permissible only if the cumulative effect of the revised allocation results in a decrease in the amount of pollutants discharged into the receiving waters, and such revised allocations are not the result of a discharger completely or substantially eliminating its discharge of pollutants.

NR 207.12(3)(b)3. 3. A less stringent effluent limitation is necessary because of events over which the permittee has no control and for which there is no reasonable available remedy.

NR 207.12(3)(b)4. 4. The permittee has received department approval for any of the following:

NR 207.12(3)(b)4.a. a. A modified technology based limitation under s. 283.13 (3), Stats.

NR 207.12(3)(b)4.b. b. An extended compliance schedule under s. 283.13 (6), Stats.

NR 207.12(3)(b)4.c. c. A modified technology based limitation under a fundamentally different factors variance under ss. NR 220.30 to 220.33.

NR 207.12(3)(b)4.d. d. An alternative thermal effluent limitation under s. 283.17 (1), Stats.

NR 207.12(3)(b)5. 5. The permittee has installed the treatment facilities required to meet the effluent limitations in the previous permit and has properly operated and maintained the facilities, but has nevertheless been unable to achieve the previous effluent limitations. In such a case, the effluent limitation in the reissued, revoked and reissued, or modified permit may be relaxed to reflect the level of pollutant control actually achieved. However, in no case may the limitation be less stringent than applicable effluent guidelines in effect at the time of reissuance or modification.

NR 207.12 Note Note: These exceptions are listed in 33 USC 1342(o)(2).

NR 207.12(4) (4) Relaxing an interim effluent limitation or an elg-based limitation or standard. Interim effluent limitations, standards, and conditions and ELG-based effluent limitations and standards that have taken effect in a permit may be relaxed in a reissued, revoked and reissued, or modified permit if the requirements in sub. (1) (a) and (b) are met and both of the following are met:

NR 207.12(4)(a) (a) Circumstances upon which the previous permit was based have materially and substantially changed since the time the permit was issued.

NR 207.12(4)(b) (b) Changes have occurred that would constitute cause for a permit modification or revocation and reissuance under ch. NR 203.

NR 207.12 Note Note: Subsection (4) addresses the requirements in 40 CFR 122.44(l)(1).

NR 207.12 History History: CR 17-002: cr. Register April 2018 No. 748, eff. 5-1-18; correction in (3) (a) 2. b. under s. 13.92 (4) (b) 7., Stats., Register April 2018.