Section 58.01.01.579 - BASELINES FOR PREVENTION OF SIGNIFICANT DETERIORATION01.Baseline Date(s). (3-28-23) a. Major Source Baseline Date. (3-28-23) i. In the case of PM10 and sulfur dioxide, January 6, 1975; (3-28-23)ii. In the case of nitrogen dioxide, February 8, 1988; and (3-28-23)iii. In the case of PM2.5, October 20, 2010. (3-28-23)b. Minor Source Baseline Date. The earliest date after the trigger date on which a major stationary source or a major modification subject to prevention of significant deterioration (PSD) submits a complete application. The trigger date is: (3-28-23)i. In the case of PM10 and sulfur dioxide, August 7, 1977; and (3-28-23)ii. In the case of nitrogen dioxide, February 8, 1988. (3-28-23)iii. In the case of PM2.5, October 20, 2011. (3-28-23)c. The baseline date is established for each pollutant for which increments or other equivalent measures have been established if: (3-28-23)i. The area in which the proposed source or modification would construct is designated as attainment or unclassifiable under Section 107(d) of the Clean Air Act for the pollutant on the date of its complete prevention of significant deterioration (PSD) application; and (3-28-23)ii. In the case of a major stationary source, the pollutant would be emitted in significant amounts, or, in the case of a major modification, there would be a significant net emissions increase of the pollutant. (3-28-23)d. Any minor source baseline date established originally for the TSP increments remains in effect and applies for purposes of determining the amount of available PM 10 increments, except that the Department may rescind any such minor source baseline date where it can be shown, to the satisfaction of the Department, that the emissions increase from the major stationary source, or the net emissions increase from the major modification, responsible for triggering that date did not result in a significant amount of PM10 emissions. (3-28-23)02.Baseline Area. Any intrastate area designated as attainment or unclassifiable under 42 U.S.C. Section 7407 (d), in which the major facility 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: Equal to or greater than 1 pg/m3 (annual average) for SO2, NO2, or PM10; or equal or greater than 0.3 ug/m3 (annual average) for PM2.5. (3-28-23)03.Baseline Concentration. The ambient concentration for a particular regulated air pollutant which exists in the applicable baseline area on the applicable minor source baseline date. (3-28-23) a. The baseline concentration represents: (3-28-23) i. The actual emissions from sources in existence on the applicable minor source baseline date; and (3-28-23)ii. The allowable emissions of major facilities and major modifications that commenced construction before the applicable major source baseline date, but were not in operation by the applicable minor source baseline date. (3-28-23)b. The baseline concentration does not include the actual emissions of new major facilities and major modifications that commenced construction on or after the applicable major source baseline date. (3-28-23)Idaho Admin. Code r. 58.01.01.579