340-224-0025 Major Modification (1) Except as provided in sections (3) and (4), "major modification" means a change at a source described in section (2) for any regulated pollutant subject to NSR since the later of: (a) The baseline period for all regulated pollutants except PM2.5; (b) May 1, 2011 for PM2.5; or (c) The most recent Major or Type A State NSR action for that regulated pollutant. (2)(a) Any physical change or change in the method of operation of a source that results in emissions described in paragraphs (A) and (B): (A) A PSEL or actual emissions that exceed the netting basis by an amount that is equal to or greater than the SER; and (B) The accumulation of emission increases due to all physical changes and changes in the method of operation that is equal to or greater than the SER. For purposes of this paragraph, emission increases shall be calculated as follows: For each unit with a physical change or change in the method of operation occurring at the source since the later of the dates in subsections (1)(a) through (1)(c) as applicable for each pollutant, subtract the unit’s portion of the netting basis from its post-change potential to emit taking into consideration any federally enforceable limits on potential to emit. Emissions from categorically insignificant activities, aggregate insignificant emissions, and fugitive emissions must be included in the calculations. (b) For purposes of this section: (A) “The unit’s portion of the netting basis” means the portion of the netting basis assigned to or associated with the unit in question, taking into consideration the following, as applicable: (i) The unit’s portion of the netting basis when the netting basis is established under OAR 340-222-0046(2); and (ii) Any adjustments under OAR 340-222-0046(3) that affect the unit’s portion of the netting basis. (B) Emission increases due solely to increased use of equipment or facilities that existed or were permitted or approved to construct in accordance with OAR 340 division 210 during the applicable baseline period are not included, except if the increased use is to support a physical change or change in the method of operation. (C) If a portion of the netting basis or PSEL or both was set based on PTE because the source had not begun normal operations but was permitted or approved to construct and operate, that portion of the netting basis or PSEL or both must be excluded until the netting basis is reset as specified in OAR 340-222-0046(3)(d) and 340-222-0051(3). (3) “Major modification” means any change including production increases, at a source that obtained a permit to construct and operate after the applicable baseline period but has not undergone Major NSR or Type A State NSR, that meets the criteria in subsections (a) or (b): (a) The change would result in a PSEL increase of the de minimis level or more for any regulated pollutant at a federal major source in attainment, unclassified or sustainment areas; or (b) The change would result in a PSEL increase of the de minimis level or more for the sustainment, nonattainment, reattainment or maintenance pollutant if the source emits such pollutant at the SER or more in a sustainment, nonattainment, reattainment, or maintenance area. (c) This section does not apply to PM2.5 and greenhouse gases. (d) Changes to the PSEL solely due to the availability of more accurate and reliable emissions information are exempt from being considered an increase under this section. (4) Major modifications for ozone precursors or PM2.5 precursors also constitute major modifications for ozone and PM2.5, respectively. (5) Except as provided in sections (1), (3), and (4), the following are not major modifications: (a), Increases in hours of operation or production rates that would cause emission increases above the levels allowed in a permit but would not involve a physical change or change in method of operation of the source. (b) Routine maintenance, repair, and replacement of components. (c) Temporary equipment installed for maintenance of the permanent equipment if the temporary equipment is in place for less than six months and operated within the permanent equipment's existing PSEL. (d) Use of alternate fuel or raw materials, that were available during, and that the source would have been capable of accommodating in the baseline period. (6) When more accurate or reliable emissions information becomes available, a recalculation of the PSEL, netting basis, and increases/decreases in emissions must be performed to determine whether a major modification has occurred. NOTE: This rule was moved verbatim from OAR 340-200-0020(71) and amended on 04-16-15. Previous rule history for OAR 340-200-0020: [DEQ 15-1978, f. & ef. 10-13-78; DEQ 4-1993, f. & cert. ef. 3-10-93; DEQ 47, f. 8-31-72, ef. 9-15-72; DEQ 63, f. 12-20-73, ef. 1-11-74; DEQ 107, f. & ef. 1-6-76; Renumbered from 340-020-0033.04; DEQ 25-1981, f. & ef. 9-8-81; DEQ 5-1983, f. & ef. 4-18-83; DEQ 18-1984, f. & ef. 10-16-84; DEQ 8-1988, f. & cert. ef. 5-19-88 (and corrected 5-31-88); DEQ 14-1989, f. & cert. ef. 6-26-89; DEQ 42-1990, f. 12-13-90, cert. ef. 1-2-91; DEQ 2-1992, f. & cert. ef. 1-30-92; DEQ 7-1992, f. & cert. ef. 3-30-92; DEQ 27-1992, f. & cert. ef. 11-12-92; DEQ 4-1993, f. & cert. ef. 3-10-93; DEQ 12-1993, f. & cert. ef. 9-24-93, Renumbered from 340-020-0145, 340-020-0225, 340-020-0305, 340-020-0355, 340-020-0460 & 340-020-0520; DEQ 19-1993, f. & cert. ef. 11-4-93; DEQ 20-1993(Temp), f. & cert. ef. 11-4-93; DEQ 13-1994, f. & cert. ef. 5-19-94; DEQ 21-1994, f. & cert. ef. 10-14-94; DEQ 24-1994, f. & cert. ef. 10-28-94; DEQ 10-1995, f. & cert. ef. 5-1-95; DEQ 12-1995, f. & cert. ef. 5-23-95; DEQ 22-1995, f. & cert. ef. 10-6-95; DEQ 19-1996, f. & cert. ef. 9-24-96; DEQ 22-1996, f. & cert. ef. 10-22-96; DEQ 9-1997, f. & cert. ef. 5-9-97; DEQ 14-1998, f. & cert. ef. 9-14-98; DEQ 16-1998, f. & cert. ef. 9-23-98; DEQ 21-1998, f. & cert. ef. 10-14-98; DEQ 1-1999, f. & cert. ef. 1-25-99; DEQ 6-1999, f. & cert. ef. 5-21-99]; DEQ 14-1999, f. & cert. ef. 10-14-99, Renumbered from 340-020-0205, 340-028-0110; DEQ 6-2001, f. 6-18-01, cert. ef. 7-1-01; DEQ 2-2005, f. & cert. ef. 2-10-05; DEQ 2-2006, f. & cert. ef. 3-14-06; DEQ 6-2007(Temp), f. & cert. ef. 8-17-07 thru 2-12-08; DEQ 8-2007, f. & cert. ef. 11-8-07; DEQ 10-2008, f. & cert. ef. 8-25-08; DEQ 5-2010, f. & cert. ef. 5-21-10; DEQ 10-2010(Temp), f. 8-31-10, cert. ef. 9-1-10 thru 2-28-11; Administrative correction 3-29-11; DEQ 5-2011, f. 4-29-11, cert. ef. 5-1-11; DEQ 7-2011(Temp), f. & cert. ef. 6-24-11 thru 12-19-11; Administrative correction, 2-6-12; DEQ 1-2012, f. & cert. ef. 5-17-12; DEQ 4-2013, f. & cert. ef. 3-27-13; DEQ 11-2013, f. & cert. ef. 11-7-13 NOTE: This rule is included in the State of Oregon Clean Air Act Implementation Plan that EQC adopted under OAR 340-200-0040. Statutory/Other Authority: ORS 468.020, 468A.025, 468A.035, 468A.040, 468A.050, 468A.055 & 468A.070 Statutes/Other Implemented: ORS 468A History: DEQ 7-2015, f. & cert. ef. 4-16-15