NR 404.04(2)(a)(a)
Primary standard. The primary standard for sulfur oxides, measured as sulfur dioxide, is 0.075 ppm — maximum 1-hour concentration. The 1-hour primary standard is met at an ambient air quality monitoring site when the 3-year average of the annual (99
th percentile) of the daily maximum 1-hour average concentrations is less than or equal to 0.075 ppm, as determined by the methodology of
40 CFR part 50, Appendix T, incorporated by reference in s.
NR 484.04 (7m).
NR 404.04(2)(b)
(b) Secondary standard. The secondary standard for sulfur oxides, measured as sulfur dioxide, is: 0.5 ppm — maximum 3-hour average concentration, not to be exceeded more than once per year.
NR 404.04(4)
(4)
Carbon monoxide: primary and secondary standards. The primary and secondary standards for carbon monoxide are:
NR 404.04(4)(a)
(a) 10 milligrams per cubic meter (9 ppm) — maximum 8-hour average concentration, not to be exceeded more than once per year.
NR 404.04(4)(b)
(b) 40 milligrams per cubic meter (35 ppm) — maximum 1-hour concentration, not to be exceeded more than once per year.
NR 404.04(5)
(5)
Ozone: primary and secondary standards. The primary and secondary standards for ozone are:
NR 404.04(5)(a)
(a) 0.12 ppm (235 micrograms per cubic meter) — maximum 1-hour average concentration. The 1-hour ozone standards are attained when the expected number of days per calendar year with maximum hourly average concentrations above the designated level is equal to or less than one, as determined by the methodology of
40 CFR part 50, Appendix H, incorporated by reference in s.
NR 484.04 (4).
NR 404.04(5)(b)
(b) 0.08 ppm — maximum 8-hour concentration. The 8-hour ozone standards are attained when the arithmetic mean of the fourth highest daily maximum 8-hour concentration at an ambient air quality monitoring site is less than or equal to 0.08 ppm, as determined by the methodology of
40 CFR part 50, Appendix I, incorporated by reference in s.
NR 484.04 (4m).
NR 404.04(5)(c)
(c) 0.075 ppm — maximum 8-hour concentration. The 8-hour primary and secondary ozone ambient air quality standards are attained at an ambient air quality monitoring site when the 3-year average of the annual fourth-highest daily maximum 8-hour average ozone concentration is less than or equal to 0.075 ppm, as determined in accordance with
40 CFR part 50, Appendix P, incorporated by reference in s.
NR 484.04 (6t).
NR 404.04(5)(d)
(d) 0.070 ppm – maximum 8-hour concentration. The 8-hour primary and secondary ozone ambient air quality standards are attained at an ambient air quality monitoring site when the 3-year average of the annual 4th-highest daily maximum 8-hour average ozone concentration is less than or equal to 0.070 ppm, as determined under
40 CFR part 50, Appendix U, incorporated by reference under s.
NR 484.04 (7s).
NR 404.04 Note
Note: The department promulgates ozone standards in response to federally promulgated ozone standards, and pursuant to its statutory obligation under s.
285.21 (1) (a), Stats., pars. (a) and (b) reflect standards from 1979 and 1997. They are included here to conform to the federal standards in
40 CFR part 50, where they are also included.
NR 404.04(6)(a)(a) Primary standards. The primary standards for nitrogen dioxide are:
NR 404.04(6)(a)1.
1. 0.053 ppm — primary annual average concentration. The primary annual standard is met when the annual average concentration in a calendar year is less than or equal to 0.053 ppm, as determined by the methodology of
40 CFR part 50, Appendix S, incorporated by reference in s.
NR 484.04 (7).
NR 404.04(6)(a)2.
2. 0.100 ppm — primary 1-hour average concentration. The primary 1-hour standard is met when the 3-year average of the annual 98th percentile of the daily maximum 1-hour average concentration is less than or equal to 0.100 ppm, as determined by the methodology of
40 CFR part 50, Appendix S, incorporated by reference in s.
NR 484.04 (7).
NR 404.04(6)(b)
(b)
Secondary standard. The secondary standard for nitrogen dioxide is 0.053 ppm. The secondary standard is attained when the annual arithmetic mean concentration in a calendar year is less than or equal to 0.053 ppm, rounded to three decimal places. Fractional parts equal to or greater than 0.0005 ppm shall be rounded up. To demonstrate attainment, an annual mean shall be based upon hourly data that are at least 75% complete or upon data derived from manual methods that are at least 75% complete for the scheduled sampling days in each calendar quarter.
NR 404.04(7)
(7)
Lead: primary and secondary standards. The primary and secondary standards for lead and its compounds, measured as elemental lead, are the following:
NR 404.04(7)(a)
(a) 1.5 micrograms per cubic meter, maximum arithmetic mean averaged over a calendar quarter, as a constituent of suspended particulate matter. The primary and secondary standards for lead and its compounds, measured as elemental lead are attained when the maximum arithmetic mean averaged over a calendar quarter is less than or equal to 1.5 micrograms per cubic meter, as determined in accordance with
40 CFR part 50, Appendix B, incorporated by reference in s.
NR 484.04 (3).
NR 404.04(7)(b)
(b) 0.15 micrograms per cubic meter – maximum arithmetic mean. The primary and secondary ambient air quality standards for lead are attained when the maximum arithmetic 3-month mean concentration for a 3-year period is less than or equal to 0.15 micrograms per cubic meter, as determined in accordance with
40 CFR part 50, Appendix R, incorporated by reference in s.
NR 484.04 (6v).
NR 404.04(8)(a)(a) The primary and secondary standards for
PM10 are 150 micrograms per cubic meter (
mg/m
3) — maximum 24-hour average concentration.
NR 404.04(8)(b)
(b) The PM
10 standards are attained when the expected number of days per calendar year with a 24-hour average concentration above 150
mg/m
3, the level designated in par.
(a), is equal to or less than one.
NR 404.04(8)(c)
(c) The expected concentrations and number of days shall be determined by the methodology contained in
40 CFR part 50, Appendix K, incorporated by reference in s.
NR 484.04 (6).
NR 404.04(9)(am)1.1. The primary standards for PM
2.5 are 12.0 micrograms per cubic meter (
mg/m
3) — annual arithmetic mean concentration and 35
mg/m
3 — 24-hour average concentration, measured in the ambient air as PM
2.5 by either of the following methods:
NR 404.04(9)(am)2.
2. The primary annual standard is met when the annual arithmetic mean concentration, as determined in accordance with
40 CFR part 50, Appendix N, is less than or equal to 12.0
mg/m
3.
NR 404.04(9)(am)3.
3. The primary 24-hour standard is met when the 98th percentile 24-hour concentration, as determined in accordance with
40 CFR part 50, Appendix N, is less than or equal to 35
mg/m
3.
NR 404.04(9)(bm)1.1. The secondary standards for PM
2.5 are 15.0
mg/m
3 annual arithmetic mean concentration and 35
mg/m
3 24-hour average concentration, measured in the ambient air as PM
2.5 by either of the following methods:
NR 404.04(9)(bm)2.
2. The secondary annual standard is met when the annual arithmetic mean concentration, as determined in accordance with
40 CFR part 50, Appendix N, is less than or equal to 15.0
mg/m
3.
NR 404.04(9)(bm)3.
3. The secondary 24-hour standard is met when the 98th percentile 24-hour concentration, as determined in accordance with
40 CFR part 50, Appendix N, is less than or equal to 35
mg/m
3.
NR 404.04 Note
Note: 40 CFR part 50, Appendices L and N are incorporated by reference in s.
NR 484.04 (6g) and (6r), respectively.
NR 404.04 History
History: Cr.
Register, March, 1972, No. 195, eff. 4-1-72; r. (1) (b)1. and 2., renum. (1) (b) 3., to be 1.,
Register, June, 1975, No. 234, eff. 7-1-75; am. (4),
Register, August, 1981, No. 308, eff. 9-1-81; reprinted to correct error in (3),
Register, November, 1981, No. 311; cr. (7),
Register, April, 1983, No. 328, eff. 5-1-83; r. (5),
Register, November, 1983, No. 335, eff. 12-1-83; am.
Register, July, 1985, No. 355, eff. 8-1-85; renum. from NR 404.03,
Register, September, 1986, No. 369, eff. 10-1-86; r. (3) (a), renum. (3) (b) to be (3) and am., cr. (8),
Register, September, 1989, No. 405, eff. 10-1-89; am. (5) and (8) (b) 3.,
Register, May, 1992, No. 437, eff. 6-1-92; am. (5) and (8) (b) 3.,
Register, December, 1995, No. 480, eff. 1-1-96; am. (8) (b),
Register, December, 1996, No. 492, eff. 1-1-97;
CR 03-066: am. (2) (a) 1. and 2. and (b), (5) and (6), cr. (5) (b)
Register May 2005 No. 593, eff. 6-1-05;
CR 07-082: am. (8), cr. (9)
Register September 2009 No. 645, eff. 10-1-09;
CR 09-088: cr. (5) (c), (7) (a) and (b), renum. (7) to be (7) (intro.) and am.
Register May 2010 No. 653, eff. 6-1-10;
CR 07-082: r. (3)
Register November 2011 No. 671, eff. 12-1-11;
CR 15-033: am. (2) (a) (title), renum. (a) (intro.) to (a) and am., r. 1. and 2., r. and recr. (6)
Register July 2016 No. 727, eff. 8-1-16;
CR 16-041: am. (9) (title), cr. (9) (am) (title), consol. (9) (a) (intro.), 1., 2. and renum. to (9) (am) 1. (intro.) and am., cr. (9) (am) 1. a., b., consol. (9) (b) (intro.), 1. and renum. to (9) (am) 2. and am., renum. (9) (b) 2. to (9) (am) 3. and am., cr. (9) (bm), r. (9) (c)
Register December 2017 No. 744, eff. 1-1-18;
CR 21-022: cr. (5) (d) Register February 2022 No. 794, eff. 3-1-22.
NR 404.05(1)(1)
Scope. The ambient air increments apply to all attainment areas of the state.
NR 404.05(2)
(2)
Class I increments. In any area of this state classified under the Act as a class I area, the ambient air increments for PM
10, PM
2.5, sulfur dioxide, and nitrogen dioxide may not exceed the following amounts:
1. Annual arithmetic mean 4 micrograms per cubic meter
2. Twenty-four hour maximum 8 micrograms per cubic meter
1. Annual arithmetic mean 1 microgram per cubic meter
2. Twenty-four hour maximum 2 micrograms per cubic meter
1. Annual arithmetic mean 2 micrograms per cubic meter
2. Twenty-four hour maximum 5 micrograms per cubic meter
3. Three hour maximum 25 micrograms per cubic meter
1. Annual arithmetic mean 2.5 micrograms per cubic meter
NR 404.05(3)
(3)
Class II increments. In any area of this state classified under the Act as a class II area, the ambient air increments for PM
10, PM
2.5, sulfur dioxide, and nitrogen dioxide may not exceed the following amounts:
1. Annual arithmetic mean 17 micrograms per cubic meter
2. Twenty-four hour maximum 30 micrograms per cubic meter
1. Annual arithmetic mean 4 micrograms per cubic meter
2. Twenty-four hour maximum 9 micrograms per cubic meter
1. Annual arithmetic mean 20 micrograms per cubic meter
2. Twenty-four maximum 91 micrograms per cubic meter
3. Three hour maximum 512 micrograms per cubic meter
1. Annual arithmetic mean 25 micrograms per cubic meter
NR 404.05(4)
(4)
Class III increments. In any area of this state classified under the Act as a class III area, the ambient air increments for PM
10, PM
2.5, sulfur dioxide, and nitrogen dioxide may not exceed the following amounts:
1. Annual arithmetic mean 34 micrograms per cubic meter
2. Twenty-four hour maximum 60 micrograms per cubic meter
1. Annual arithmetic mean 8 micrograms per cubic meter
2. Twenty-four hour maximum 18 micrograms per cubic meter
1. Annual arithmetic mean 40 micrograms per cubic meter
2. Twenty-four hour maximum 182 micrograms per cubic meter
3. Three hour maximum 700 micrograms per cubic meter
1. Annual arithmetic mean 50 micrograms per cubic meter
NR 404.05(5)
(5)
Exception for non-annual concentrations. Notwithstanding subs.
(2) (intro.),
(3) (intro.) and
(4) (intro.), the ambient air increment of an air contaminant based on concentrations for any period other than an annual period may be exceeded during one such period per year.
NR 404.05(6)
(6)
Maximum concentration. The maximum allowable concentration of any air contaminant in any attainment area may not exceed a concentration for such contaminant for each period of exposure equal to the maximum concentrations permitted under the primary or secondary air standards in s.
NR 404.04.
NR 404.05 History
History: Cr.
Register, April, 1983, No. 238, eff. 5-1-83; renum. from NR 155.035,
Register, July, 1985, No. 355, eff. 8-1-85; renum. from NR 404.04,
Register, September, 1986, No. 369, eff. 10-1-86; am. (2) (intro.), (3) (intro.) and (4) (intro.), cr. (2) (c), (3) (c) and (4) (c),
Register, May, 1992, No. 437, eff. 6-1-92; am. (2) (intro.), (a), (3) (intro.), (a), (4) (intro.), (a),
Register, April, 1995, No. 472, eff. 5-1-95; am. (3) (intro.) and (4) (intro.),
Register, December, 1996, No. 492, eff. 1-1-97;
CR 15-077: am. (2) (intro.), cr. (2) (am), am. (3) (intro.), cr. (3) (am), am. (4) (intro.), cr. (4) (am)
Register July 2016 No. 727, eff. 8-1-16.
NR 404.06
NR 404.06 Measurement of ambient air quality. NR 404.06(1)(a)(a) The department and any person conducting ambient air quality monitoring on its behalf shall use only reference or equivalent methods as specified in sub.
(2) or
(3) for all ambient air quality monitoring for any air contaminant identified in s.
NR 404.04. The ambient monitoring shall conform with the department's guidebooks, plans and procedures for air monitoring quality assurance.
NR 404.06(1)(b)
(b) Any person required by the department to conduct ambient air quality monitoring shall use only reference or equivalent methods for sampling and analysis as specified in sub.
(2) or
(3) and shall comply with quality assurance and quality control procedures and the data reporting format which are specified and approved by the department for the collection, analysis, processing and reporting of ambient air quality monitoring data.
NR 404.06(1)(c)
(c) Any person who voluntarily conducts ambient air quality monitoring in Wisconsin may request the department to determine that the data being collected are comparable to the air quality data collected under par.
(a) or
(b). The department may determine that the data are comparable if the voluntary ambient air quality monitoring and the data meet the requirements specified in par.
(b).
NR 404.06(1)(d)
(d) The department may determine that air quality data submitted to the department for purposes of demonstrating compliance with existing regulations under chs.
NR 400 to
499 or in support of a permit or permit application are unacceptable if such monitoring was not conducted in compliance with pars.
(a) to
(c).
NR 404.06(2)
(2)
Reference methods. Ambient air quality monitoring which utilizes a reference monitoring method shall use monitoring methods which conform to the federal reference methods which are specified in
40 CFR part 50, Appendices A to T, incorporated by reference in s.
NR 484.04 (2), or which have been so designated by the department.
