SIP - ALASKA - 18 AAC 50.020
18 AAC 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 Dates
Air Quality Control
Region | Air Pollutant | Baseline Date |
Cook Inlet Intrastate Air
Quality Control Region | Nitrogen dioxide | February 8, 1988 |
 | Sulfur dioxide | October 12, 1979 |
| PM-10 | March 20, 1982 |
Northern Alaska Intrastate Air Quality Control
Region | Nitrogen dioxide | February 8, 1988 |
| Sulfur dioxide | June 1, 1979 |
| PM-10 | November 13, 1978 |
| South Central Alaska Intrastate Air Quality Control Region | Nitrogen dioxide | February 8, 1988 |
| Sulfur dioxide | October 26, 1979 |
| PM-10 | October 26, 1979 |
| Southeast Alaska Intrastate Air Quality Control Region | Nitrogen dioxide | February 8, 1988 |
| Sulfur dioxide | November 10, 1986 |
| PM-10 | The earliest date upon which the department declares complete an application for a facility or modification that includes information required under 18 AAC 50.306 and shows an increase in actual PM-10 emissions equal to or exceeding 15 tons per year. |
(b) To establish standards for the prevention of significant deterioration of air quality,
(1) baseline dates for determining the ambient concentration of certain air pollutants are established for each air quality control region 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; and
(4) the baseline concentrations and maximum allowable increases shall be measured or predicted by a method described in 18 AAC 50.215.
Table 3. Maximum Allowable Increases
Classification of area in 18 AAC 50.015(c) Table 1 | Air Pollutant | Maximum allowable increase (micrograms per cubic meter) |
CLASS I | PM-10:
Annual arithmetic mean..............
24-hour maximum..................... | .......4
.......8 |
| Sulfur dioxide:
Annual arithmetic mean..............
24-hour maximum.....................
3-hour maximum....................... | ......2
......5
......25 |
| Nitrogen Dioxide:
Annual arithmetic mean.............. | ......2.5 |
CLASS II | PM-10:
Annual arithmetic mean..............
24-hour maximum..................... | ......17
......30 |
| Sulfur dioxide:
Annual arithmetic mean..............
24-hour maximum.....................
3-hour maximum....................... | ......20
......91
......512 |
| Nitrogen Dioxide:
Annual arithmetic mean.............. | ......25 |
CLASS III | PM-10:
Annual arithmetic mean.............
24-hour maximum.................... | ......34
......60 |
| Sulfur dioxide:
Annual arithmetic mean............
24-hour maximum....................
3-hour maximum...................... | ......40
......182
......700 |
| Nitrogen Dioxide:
Annual arithmetic mean............ | ......50 |
(c) Repealed 10/1/2004.
(d) Repealed 10/1/2004.
(e) For purposes of this section, the baseline concentration of an air pollutant is determined as follows:
(1) for PM-10 and sulfur dioxide, the baseline concentration is the ambient concentration of the air pollutant on the applicable baseline date, plus the contribution from allowable emissions of a PSD major stationary source for which construction commenced before January 6, 1975, but that was not in operation by the baseline date; however, the baseline concentration does not include actual emissions from a PSD major stationary source or a PSD major modification for which construction commenced on or after January 6, 1975; and
(2) for nitrogen dioxide, the baseline concentration is the ambient concentration of the air pollutant on the applicable baseline date, plus the contribution from allowable emissions of a PSD major stationary source for which construction commenced before February 8, 1988, but that was not in operation by the baseline date.
(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.
State effective: 10/1/04; EPA effective: 9/13/07