Chapter NR 408

NR 408.02(29s)(c) (c) The replacement does not change any of the basic design parameters of the process line.

NR 408.02(29s)(d) (d) The replaced emissions unit is permanently removed from the major stationary source, otherwise permanently disabled, or permanently barred from operation by a permit that is enforceable as a practical matter. If the replaced emissions unit is brought back into operation, it shall constitute a new emissions unit.

NR 408.02(30) (30) “Representative actual annual emissions” means the average rate, in tons per year, at which the source is projected to emit a pollutant for the 2-year period after a physical change or change in the method of operation of a unit, or a different consecutive 2-year period within 10 years after that change, where the department determines that the period is more representative of normal source operations, considering the effect any change will have on increasing or decreasing the hourly emissions rate and on projected capacity utilization. In projecting future emissions the department shall:

NR 408.02(30)(a) (a) Consider all relevant information, including but not limited to, historical operational data, the company’s own representations, filings with the state or federal regulatory authorities, and compliance plans under title IV of the act.

NR 408.02(30)(b) (b) Exclude, in calculating any increase in emissions that results from the particular physical change or change in the method of operation at an electric utility steam generating unit, that portion of the unit’s emissions following the change that could have been accommodated during the representative baseline period and is attributable to an increase in projected capacity utilization at the unit that is unrelated to the particular change, including any increased utilization due to the rate of electricity demand growth for the utility system as a whole.

NR 408.02(31) (31) “Secondary emissions” means emissions which would occur as a result of the construction or operation of a major source or major modification, but do not come from the major source or major modification itself. For the purpose of this chapter, secondary emissions shall be specific, well defined, quantifiable and impact the same general area as the stationary source or modification which causes the secondary emissions. Secondary emissions include emissions from any off-site support facility which would not be constructed or increase its emissions except as a result of the construction or operation of the major source or major modification. Secondary emissions do not include tailpipe emissions from any source regulated under title II of the Act or any emissions from in-transit marine vessels.

NR 408.02(32) (32) 

NR 408.02(32)(a) (a) “Significant” means, in reference to a net emissions increase or the potential of a source to emit any of the following pollutants, a rate of emissions that would equal or exceed any of the following, except as provided in pars. (b) to (h):

NR 408.02(32)(a)1. 1. Carbon monoxide: 100 tons per year (tpy).

NR 408.02(32)(a)2. 2. Nitrogen oxides: 40 tpy.

NR 408.02(32)(a)3. 3. Sulfur dioxide: 40 tpy.

NR 408.02(32)(a)4. 4. Particulate matter: 25 tpy.

NR 408.02(32)(a)5. 5. PM10: 15 tpy.

NR 408.02(32)(a)5m. 5m. PM2.5: 10 tpy; 40 tpy for nitrogen oxides; and 40 tpy for sulfur dioxide.

NR 408.02(32)(a)6. 6. Ozone: 40 tpy of VOC or 40 tpy of nitrogen oxides.

NR 408.02(32)(a)7. 7. Lead: 0.60 tpy.

NR 408.02(32)(b) (b) Notwithstanding the significant emission rate for carbon monoxide under par. (a), a net increase in carbon monoxide emissions resulting from any physical change in, or change in the method of operation of, a stationary source in a serious nonattainment area for carbon monoxide is significant if the increase exceeds 50 tpy, provided stationary sources contribute significantly to carbon monoxide levels in that area.

NR 408.02 Note Note: If any serious nonattainment area for carbon monoxide is designated in the state, the department will make the determination of whether stationary sources contribute significantly to the carbon monoxide levels in accordance with rules or guidance issued by the U.S. environmental protection agency.

NR 408.02(32)(c) (c) Notwithstanding the significant emissions rate for ozone under par. (a), a net increase in emissions of VOCs that would result from any physical change in, or change in the method of operation of, a stationary source for which a complete construction permit application was submitted or was required to be submitted after November 15, 1992 and which is located in a serious or severe nonattainment area for ozone is significant if the increase exceeds 25 tpy when aggregated with all creditable increases and decreases in emissions of that precursor from the source over any period of 5 consecutive years, which includes the calendar year in which the increase will occur.

NR 408.02(32)(d) (d) Notwithstanding the significant emissions rates for ozone under pars. (a) and (c), any increase in VOC emissions from any discrete operation, unit or other pollutant emitting activity at a major source of VOCs located in an extreme nonattainment area for ozone shall be considered significant.

NR 408.02(32)(e) (e) Notwithstanding the significant emission rates for PM10 under par. (a), a net increase in PM10 emission resulting from a physical change in, or a change in the method of operation of, a stationary source in a serious nonattainment area for PM10 is significant if the increase exceeds 10 tpy.

NR 408.02(32)(f) (f) For the purposes of applying the requirements of s. NR 408.03 (5) to major sources of nitrogen oxides for which a complete construction permit application was submitted or was required to be submitted after November 15, 1992 and which are located in ozone nonattainment areas or in ozone transport regions, the significant emission rates and other requirements for VOC in this subsection shall apply to nitrogen oxides emissions.

NR 408.02(32)(g) (g) For the purposes of applying the requirements of s. NR 408.03 (4) to a major source of a PM10 precursor located in a moderate PM10 nonattainment area, the significant emission rate for the PM10 precursor is 15 tpy.

NR 408.02(32)(h) (h) For the purposes of applying the requirements of s. NR 408.03 (4) to a major source of a PM10 precursor located in a serious PM10 nonattainment area, the significant emission rate for the PM10 precursor is 10 tpy.

NR 408.02(32m) (32m) “Significant emissions increase” means, for a regulated NSR air contaminant, an increase in emissions that is equal to or greater than the value for that air contaminant listed in s. NR 408.02 (32).

NR 408.02(33) (33) “Temporary clean coal technology demonstration project” means a clean coal technology demonstration project that is operated for a period of 5 years or less, and which complies with the state implementation plan and other requirements necessary to attain and maintain the national ambient air quality standards during the project and after it is terminated.

NR 408.02 History History: Cr. Register, May, 1993, No. 449, eff. 6-1-93; am. (21) (a) 1. intro., cr. (21) (f), Register, June, 1995, No. 474, eff. 7-1-95; am. (4), (5), (20) (e) 5. a. and b., (21) (intro.), Register, December, 1995, No. 480, eff. 1-1-96; am. (1)(b), (c), (4), (6), (8) (intro.), (20) (e) 2., 3., 8., 9. (intro.), (21) (b) 1. a., (e) 29., (23) (b) (intro.), 1., (24) (a), (b) 1., (25), (29), Register, December, 1996, No. 492, eff. 1-1-97; CR 01-081: am. (2) (a) and (4) Register September 2004 No. 585, eff. 10-1-04; CR 03-118: am. (1), (4), (5), (11), (13) and (21) (a) 1., cr. (2m), (11e), (11m), (11s), (13m), (24m), (25s), (28e), (28j), (28m), (28s), (29m) and (32m), r. and recr. (20) and (23), r. (27), Register June 2007 No. 618, eff. 7-1-07; CR 07-104: am. (13) (b) and (21) (e) 5., cr. (29s) Register July 2008 No. 631, eff. 8-1-08; CR 07-036: am. (2) (a) and (4) Register November 2008 No. 635, eff. 12-1-08; CR 10-050: cr. (32) (a) 5m. Register November 2010 No. 659, eff. 12-1-10; CR 13-070: am. (20) (e) 5. a., b., 6., renum. (29m) (c) to (c) (intro.) and am., cr. (29m) (c) 1. to 3., (d) Register July 2014 No. 703, eff. 8-1-14; CR 21-022: cr. (24) (c), am. (32) (a) 6. Register February 2022 No. 794, eff. 3-1-22.

NR 408.025 NR 408.025 Methods for calculation of increases in actual emissions.

NR 408.025(1) (1) For projects that only involve existing emissions units, any increase in actual emissions from a physical change or change in the method of operation at a stationary source shall equal the sum of the difference between the projected actual emissions and the baseline actual emissions for each existing emissions unit involved in the project.

NR 408.025(2) (2) For projects that only involve construction of a new emissions unit or units, any increase in actual emissions from a physical change or change in the method of operation at a stationary source shall equal the sum of the differences between the potential to emit from each new emissions unit following completion of the project and the baseline actual emissions for each unit before the project.

NR 408.025(3) (3) For projects that involve existing and new emissions units, any increase in actual emissions from a physical change or change in the method of operation at a stationary source shall equal the sum of the emissions increases for each emissions unit involved in the project, using the method specified in sub. (1) for existing emissions units and the method in sub. (2) for new emissions units.

NR 408.025 History History: CR 03-118: cr. Register June 2007 No. 618, eff. 7-1-07.

NR 408.03 NR 408.03 Source applicability and exemptions.

NR 408.03(1) (1) No person may begin actual construction of a major source or major modification to which the requirements of this chapter apply unless the person has a permit which states that the stationary source or modification will meet the requirements of ss. NR 408.04 to 408.10.

NR 408.03(2) (2) The requirements of ss. NR 408.04 to 408.10 shall apply only to any new major source or major modification that is major for the pollutant, or the precursor of the pollutant, as applicable, for which an area is designated as nonattainment, or as an ozone transport region, as of the date the permit is issued, if the stationary source or modification would be constructed anywhere in the designated nonattainment area or ozone transport region.

NR 408.03(3) (3) The requirements of ss. NR 408.04 to 408.10 shall apply with respect to any air contaminant for which an applicable source is major and in the case of a modification, would result in a significant net emissions increase for that pollutant.

NR 408.03(4) (4) The requirements of ss. NR 408.04 to 408.10 applicable to new major sources or major modifications of PM10 shall also apply to each PM10 precursor for which the source is a major source, except that the requirements do not apply where the administrator determines that the sources of PM10 precursors do not significantly contribute to PM10 levels which exceed the PM10 ambient standards.

NR 408.03(5) (5) The requirements of ss. NR 408.04 to 408.10 applicable for new major sources or major modifications of VOC shall apply to nitrogen oxides emissions from new major sources or major modifications of nitrogen oxides, except that the requirements do not apply if the administrator determines, when the administrator approves a plan, plan revision or petition under provisions of section 182 (f) of the Act (42 USC 7511a(f)), that the statutory requirements of section 182 (f) do not apply.

NR 408.03(6) (6) For any major modification which results in a significant net emissions increase of VOCs in a serious or severe nonattainment area for ozone, if the source’s potential to emit is less than 100 tpy of VOCs, the requirements of ss. NR 408.04 to 408.10 will not apply with respect to the VOCs if the owner or operator of the source elects to offset the increase in VOC emissions by a greater reduction in emissions of VOCs from other operations, units or activities within the source, at an internal offset ratio of at least 1.3 to 1.

NR 408.03(7) (7) Notwithstanding the requirements for offsets under s. NR 408.06, emission offsets for an increase in the emissions of VOCs will not be required for a major modification which results in a significant increase in VOC emissions in an extreme nonattainment area for ozone if the modification consists of the installation of equipment required to comply with the applicable implementation plan, permit or provision under the act.

NR 408.03(8) (8) The provisions of this chapter do not apply to a source or modification that would be a major source or major modification only if fugitive emissions to the extent quantifiable are considered in calculating the potential to emit of the stationary source or modification and the source does not belong to any of the source categories contained in s. NR 408.02 (21) (e).

NR 408.03(9) (9) For attainment or unclassifiable areas within an ozone transport region, the permitting requirements of both ch. NR 405 and this chapter shall apply and where requirements conflict or overlap, the more stringent requirements shall prevail.

NR 408.03 History History: Cr. Register, May, 1993, No. 449, eff. 6-1-93; am. (5), Register, December, 1996, No. 492, eff. 1-1-97.

NR 408.04 NR 408.04 Control technology review.

NR 408.04(1) (1) A major source or major modification shall meet each applicable emission limitation under this chapter and each applicable emission standard or standard of performance under chs. NR 440 and 447 to 449 and subch. IV of ch. NR 446.

NR 408.04(2) (2) A new major source shall apply the lowest achievable emission rate for each pollutant subject to the provisions of this chapter that it would have the potential to emit in an amount which makes the source a major source. This provision applies to each new emissions unit at which emission increases would occur.

NR 408.04(3) (3) A major modification shall apply the lowest achievable emission rate for each pollutant subject to the requirements of this chapter for which it would result in a significant net emissions increase at the source. This requirement applies to each emissions unit at which a net emissions increase in the pollutant would occur as a result of a physical change or change in the method of operation in the unit.

NR 408.04(4) (4) For phased construction projects, the determination of the lowest achievable emission rate shall be reviewed and modified as appropriate at the latest reasonable time which occurs no more than 18 months prior to commencement of construction of each independent phase of the project. At the time of the review, the owner or operator of the affected stationary source may be required to demonstrate the adequacy of any previous determination of the lowest achievable emission rate for the source.

NR 408.04(5) (5) In the case of any major modification which results in a significant net emissions increase in VOC emissions in a serious or severe nonattainment area for ozone, if the modification occurs at a source which emits or has the potential to emit 100 tons or more of the VOCs per year, the requirements of sub. (3), concerning compliance with the lowest achievable emission rate, will not apply if the owner or operator of the source elects to offset the increase of emissions of the VOCs by a greater reduction in emissions of VOCs from other operations, units or pollutant emitting activities within the source at an internal offset ratio of at least 1.3 to 1.

NR 408.04(6) (6) In the case of any major modification which results in a significant net emissions increase in VOC emissions in a serious or severe nonattainment area for ozone, if the source’s potential to emit is less than 100 tpy of VOCs, the source shall be required to comply with BACT as a substitute for the LAER otherwise required under sub. (3).

NR 408.04(7) (7) The department shall, for each new major source and major modification, submit to the U.S. environmental protection agency, within 60 days of issuance of the construction permit, all information on the emissions prevention or control technology for the new major source or major modification.

NR 408.04 Note Note: The data submitted by the department will be included in the U.S. environmental protection agency’s RACT/BACT/LAER Clearinghouse.

NR 408.04 History History: Cr. Register, May, 1993, No. 449, eff. 6-1-93; CR 01-081: am. (1) Register September 2004 No. 585, eff. 10-1-04; CR 07-036: am. (1) Register November 2008 No. 635, eff. 12-1-08.

NR 408.05 NR 408.05 Reasonable further progress.

NR 408.05(1) (1) By the time the proposed major source or major modification is to commence operation, sufficient offsetting emissions shall be in effect such that the total emissions from existing sources in the area, from new or modified sources which are not major sources and from the proposed source will be sufficiently less than total emissions from existing sources prior to the application for the permit to construct or modify so as to represent, when considered together with the plan provisions required under section 172 of the Act (42 USC 7502), reasonable further progress.

NR 408.05(2) (2) For the purposes of satisfying the requirements of sub. (1):

NR 408.05(2)(a) (a) The determination of total emissions at both the time prior to the application for a permit subject to the requirements of this chapter and the time the permitted source or modification would commence operation, shall be made in a manner consistent with the assumptions in the applicable state implementation plan approved by the administrator concerning baseline emissions for the demonstration of reasonable further progress and attainment of the national ambient air quality standards for the particular pollutant subject to review under this chapter.

NR 408.05(2)(b) (b) To demonstrate reasonable further progress a new or modified source subject to review under this chapter shall obtain offsets in an amount equal to or greater than the amount specified by the applicable offset ratio. If an offset ratio is not specified, the offset ratio shall be at least 1 to 1.

NR 408.05 History History: Cr. Register, May, 1993, No. 449, eff. 6-1-93; am. (1), Register, December, 1996, No. 492, eff. 1-1-97.

NR 408.06 NR 408.06 Emissions offsets.

NR 408.06(1) (1) To be eligible for use under this chapter, emissions offsets shall meet all of the following criteria:

NR 408.06(1)(a) (a) Except as provided in par. (cm), offsets shall be of the same air contaminant class, that is, volatile organic compounds, particulate matter, carbon monoxide, nitrogen oxides, sulfur dioxide, or lead.

NR 408.06(1)(b) (b) Offsets for particulate matter, carbon monoxide, nitrogen oxides, sulfur dioxide and lead shall be in a time frame compatible with the applicable air quality standard.

NR 408.06(1)(c) (c) Offsets for volatile organic compounds and nitrogen oxides, where applicable, shall be quantified on an annual basis. In addition, the source shall submit emission estimates in a time frame consistent with the air quality standard for ozone.

NR 408.06 Note Note: The time frame for the air quality standard for each pollutant is given in s. NR 404.04.

NR 408.06(1)(cm) (cm) PM2.5 emission increases may be offset by decreases in nitrogen oxides or sulfur dioxide emissions, that are otherwise creditable, at a ratio of 40 tpy of sulfur dioxide for each ton of direct PM2.5 emissions and 200 tpy of nitrogen oxides for each ton of direct PM2.5 emissions.

NR 408.06(1)(d) (d) Offsets shall result in a net air quality benefit.

NR 408.06 Note Note: The term “net air quality benefit” will be interpreted based on EPA’s December 4, 1986 Emission Trading Policy Statement, incorporated by reference in s. NR 484.06, until revised by EPA or until the term is defined by the department.

NR 408.06(1)(e) (e) The emission reductions used as offsets shall be generated after the date used as a baseline or shall be included in the baseline for the portion of the latest state implementation plan which relates to the nonattainment status of the area. Emission reductions occurring before August 7, 1977 may not be used as offsets.

NR 408.06(1)(f) (f) The assumptions used to calculate the offset shall be consistent with the assumptions used to develop the area’s implementation plan.

NR 408.06(1)(g) (g) Offsets shall be surplus, permanent, quantifiable and federally enforceable at the time of their use.

NR 408.06(2) (2) Prior to the issuance of a permit under this chapter, federally enforceable emissions offsets shall be obtained from the same source or other sources in the same nonattainment area, except that the emissions offsets may be obtained from a source in another nonattainment area if both of the following apply:

NR 408.06(2)(a) (a) The other area has an equal or higher nonattainment classification than the area in which the source is located.

NR 408.06(2)(b) (b) Emissions from the other area contribute to a violation of a national ambient air quality standard in the nonattainment area in which the proposed new or modified source would be constructed.

NR 408.06(3) (3) The total annual tonnage of emissions of any applicable air contaminant allowed from the proposed new source, or net emissions increase from the modification, shall be offset by an equal or greater reduction, as applicable, in the actual emissions of the air contaminant from the same or other sources.

NR 408.06(4) (4) In meeting the requirements of sub. (3) for ozone nonattainment areas classified under section 182 of the Act (42 USC 7511a), the ratio of total actual emission reductions of VOCs, and nitrogen oxides where applicable, to the net emissions increase for the same air contaminant class shall be as follows:

NR 408.06(4)(a) (a) In any rural transport or marginal nonattainment area for ozone: at least 1.1 to 1.

NR 408.06(4)(b) (b) In any moderate nonattainment area for ozone: at least 1.15 to 1.

NR 408.06(4)(c) (c) In any serious nonattainment area for ozone: at least 1.2 to 1.

NR 408.06(4)(d) (d) In any severe nonattainment area for ozone: at least 1.3 to 1.

NR 408.06(4)(e) (e) In any extreme nonattainment area for ozone: at least 1.5 to 1.

NR 408.06(5) (5) Within an ozone transport region, for any area designated as ozone attainment, unclassifiable, or rural transport or marginal nonattainment, the ratio of total actual emissions reductions of VOCs, and nitrogen oxides where applicable, to the net emissions increase for the same air contaminant class shall be at least 1.15 to 1.

NR 408.06(6) (6) A major modification which has a significant net emissions increase of VOCs, or nitrogen oxides where applicable, which is located in an extreme nonattainment area for ozone will be considered to comply with the offset requirements under s. NR 408.05 if the owner or operator of the source elects to offset the proposed emissions increase of VOCs, and nitrogen oxides where applicable, by a greater reduction in actual emissions from other discrete operations, units or pollutant emitting activities within the source at an internal offset ratio at least 1.3 to 1.

NR 408.06(7) (7) 

NR 408.06(7)(a) (a) Emissions reductions achieved by shutting down an existing source or curtailing production or operating hours below baseline levels may be generally credited if:

NR 408.06(7)(a)1. 1. The reductions are surplus, permanent, quantifiable and federally enforceable.

NR 408.06(7)(a)2. 2. The area has a U.S. environmental protection agency approved state implementation plan, except as provided in par. (b).

NR 408.06(7)(a)3. 3. The source notifies the department in writing prior to the date the shut down or curtailment occurs. The notification shall include documentation of the type and quantity of emission reduction credit to be generated.

NR 408.06(7)(a)4. 4. The shutdown or curtailment occurs on or after the date specified for this purpose in the state implementation plan, and if the date specified is on or after the date of the most recent emissions inventory used in the plan’s demonstration of attainment. The department may consider a prior shutdown or curtailment to have occurred after the date of its most recent emissions inventory, if the inventory explicitly includes as current existing emissions the emissions from the previously shut down or curtailed sources. However, no credit is available for shutdowns which occurred prior to August 7, 1977.