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 µg/m3. 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 µg/m3. NR 404.04(9)(bm)1.1. The secondary standards for PM2.5 are 15.0 µg/m3 annual arithmetic mean concentration and 35 µg/m3 24-hour average concentration, measured in the ambient air as PM2.5 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 µg/m3. 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 µg/m3. NR 404.04 NoteNote: 40 CFR part 50, Appendices L and N are incorporated by reference in s. NR 484.04 (6g) and (6r), respectively. NR 404.04 HistoryHistory: 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 PM10, PM2.5, 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 PM10, PM2.5, sulfur dioxide, and nitrogen dioxide may not exceed the following amounts: