Section 18.50.020. Baseline dates and maximum allowable increases.

	(a)  In an area designated nonattainment in 18 AAC 50.015(b), the provisions of this section do not apply to the nonattainment air pollutant.  However, this section does  apply to all other air pollutants listed in Table 2 in this subsection.  
Table 2 
Baseline Areas and Dates   
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	(b)  To establish standards for the prevention of significant deterioration of air quality,  
		(1) minor source baseline dates for determining the ambient concentration of certain air pollutants are established for each baseline area listed in Table 2 in (a) of this section;  
		(2) in areas designated as Class I, II, or III, increases in air pollutant concentration over the baseline concentration shall be limited to the concentrations in Table 3 in this subsection;  
		(3) for any period other than an annual period, the applicable maximum allowable increase may be exceeded during one such period per year at any one location;  
		(4) the baseline concentrations and maximum allowable increases shall be measured or predicted by a method described in 18 AAC 50.215; and  
		(5) a concentration may not exceed the ambient air quality standard described in 18 AAC 50.010 for that pollutant.  
Table 3 
Maximum Allowable Increases  
  Classification of area                                   Maximum allowable
   in 18 AAC 50.015(c)             Air Pollutant         increase (micrograms
         Table 1                                           per cubic meter)
                           PM-10:
                           Annual arithmetic mean .....   ................. 4
                           24-hour maximum ............   ................. 8
                           Sulfur dioxide:
         CLASS I           Annual arithmetic mean .....   ................. 2
                           24-hour maximum ............   ................. 5
                           3-hour maximum .............   ................ 25
                           Nitrogen dioxide:
                           Annual arithmetic mean .....   ............... 2.5
                           PM-2.5:
                           Annual arithmetic mean .....   ................. 1
                           24-hour maximum ............   ................. 2
                           PM-10:
                           Annual arithmetic mean .....   ................ 17
                           24-hour maximum ............   ................ 30
                           Sulfur dioxide:
         CLASS II          Annual arithmetic mean .....   ................ 20
                           24-hour maximum ............   ................ 91
                           3-hour maximum .............   ............... 512
                           Nitrogen dioxide:
                           Annual arithmetic mean .....   ................ 25
                           PM-2.5:
                           Annual arithmetic mean .....   ................. 4
                           24-hour maximum ............   ................. 9
                           PM-10:
                           Annual arithmetic mean .....   ................ 34
                           24-hour maximum ............   ................ 60
                           Sulfur dioxide:
        CLASS III          Annual arithmetic mean .....   ................ 40
                           24-hour maximum ............   ............... 182
                           3-hour maximum .............   ............... 700
                           Nitrogen dioxide:
                           Annual arithmetic mean .....   ................ 50
                           PM-2.5:
                           Annual arithmetic mean .....   ................. 8
                           24-hour maximum ............  ................. 18
	(c)  Repealed 10/1/2004.  
	(d)  Repealed 10/1/2004.  
	(e)  For purposes of this section, the baseline concentrations within a baseline area are determined in accordance with 40 C.F.R. 52.21(b)(13), adopted by reference in 18 AAC 50.040(h).  
	(f)  In this section "commence" has the meaning given in 40 C.F.R. 52.21(b), adopted by reference in 18 AAC 50.040.  
	(g)  For purposes of this section, the baseline area is every part of an air quality control region described in 18 AAC 50.015 that is designated as attainment or unclassifiable, and in which the major source or major modification establishing the minor source baseline date would construct or would have an air quality impact for the pollutant for which the baseline date is established, as follows:  
		(1) equal to or greater than one microgram per cubic meter on an annual average basis for sulfur dioxide, nitrogen dioxide, or PM-10;  
		(2) equal to or greater than 0.3 micrograms per cubic meter on an annual average basis for PM-2.5.  

Authorities

46.03.020;46.14.010;46.14.030

Notes

Reference

18 AAC 50.040
18 AAC 50.055
18 AAC 50.215
18 AAC 50.306
18 AAC 63.110

Authority

AS 46.03.020 AS 46.14.010 AS 46.14.030

History

Eff. 1/18/97, Register 141; am 6/21/98, Register 146; am 10/1/2004, Register 171; am 7/25/2008, Register 187; am 1/4/2013, Register 205; am 4/17/2015, Register 214; am 8/20/2016, Register 219