340-225-0045
Requirements for Analysis in Maintenance Areas
340-225-0045
Requirements for Analysis in Maintenance Areas
Modeling: For determining compliance with the NAAQS and PSD increments, the owner or operator must conduct the modeling required by OAR 340-225-0050(1) and (2). For determining compliance with the maintenance area limits established in OAR 340-202-0225, the following methods must be used:
(1) For each maintenance area pollutant and its precursors, a single source impact analysis is sufficient to show compliance with the maintenance area limits if modeled impacts from emission increases equal to or greater than a SER above the netting basis due to the proposed source or modification being evaluated are less than the Class II Significant Impact Levels specified in OAR 340-200-0020 and the owner or operator provides a demonstration that the SIL by itself is protective of the maintenance area limits. The demonstration must include, but is not limited to the following:
(a) an evaluation of the background ambient concentration relative to the maintenance area limit;
(b) an evaluation of the emission increases and decreases from other sources within the range of influence since the area was designated as a maintenance area; and
(c) a discussion of other factors that could contribute to a violation of the maintenance area limits, such as proximity to existing emission sources, topography, and meteorological conditions.
(2) If the requirement in section (1) is not satisfied, , the owner or operator of a proposed source or modification must show that modeled impacts from the proposed increased emissions plus competing source impacts, plus the predicted maintenance area concentration are less than the limits in OAR 340-202-0225 for all averaging times.
[ED. NOTE: Tables referenced are available from the agency.]
Stat. Auth.: ORS 468.020
Stats. Implemented: ORS 468A, 468A.025 & 468A.035
Hist.: DEQ 11-2002, f. & cert. ef. 10-8-02; DEQ 1-2005, f. & cert. ef. 1-4-05; 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
340-225-0050
Requirements for Analysis in PSD Class II and Class III Areas
Modeling: For determining compliance with the NAAQS and PSD Increments in PSD Class II and Class III areas, the following methods must be used:
(1) For each pollutant and its precursors, a single source impact analysis is sufficient to show compliance with standards and PSD increments if modeled impacts from emission increases equal to or greater than a significant emission rate above the netting basis due to the proposed source or modification being evaluated are less than the Class II Significant Air Quality Impact Levels specified in OAR 340-200-0020, Table 1and the owner or operator provides a demonstrating that the SIL by itself is protective of the NAAQS and PSD increments. The demonstration must include, but is not limited to the following:
(a) an evaluation of the background ambient concentration relative to the NAAQS;
(b) an evaluation of the emission increases and decreases from other sources within the range of influence since the baseline concentration year; and
(c) a discussion of other factors that could contribute to a violation of the NAAQS or PSD increment, such as proximity to existing emission sources, topography, and meteorological conditions.
(2) If the requirement in section (1) of this rule is not satisfied, the owner or operator of a proposed source or modification being evaluated must perform competing source modeling as follows:
(a) For demonstrating compliance with the PSD Increments (as defined in OAR 340-202-0210, Table 1), the owner or operator of a proposed source or modification must show that modeled impacts from the proposed increased emissions (above the modeled Baseline Concentration) plus Competing PSD Increment Consuming Source Impacts (above the modeled Baseline Concentration) are less than the PSD increments for all averaging times.
(b) For demonstrating compliance with the NAAQS, the owner or operator of a proposed source must show that the total modeled impacts plus total Competing NAAQS Source Impacts plus General Background Concentrations are less than the NAAQS for all averaging times.
(3) The owner or operator must not cause or contribute to a new violation of an ambient air quality standard or PSD increment even if the single source impact is less than the significant impact level, in accordance with OAR 340-202-0050(2).
(4) Additional Impact Modeling:
(a) When referred to this rule by divisions 222 or 224, the owner or operator of a source must provide an analysis of the impairment to visibility, soils and vegetation that would occur as a result of the source or modification, and general commercial, residential, industrial and other growth associated with the source or modification. As a part of this analysis, deposition modeling analysis is required for sources emitting heavy metals above the significant emission rates as defined in OAR 340-200-0020, Table 2. Concentration and deposition modeling may also be required for sources emitting other compounds on a case-by-case basis;
(b) The owner or operator must provide an analysis of the air quality concentration projected for the area as a result of general commercial, residential, industrial and other growth associated with the source or modification.
jinahar, 2013-11-13T08:56:00Z
Mark – fix language for SIL modeling here and in 225-0050
mfisher, 2013-11-13T10:01:00Z
This paragraph can be removed. NAAQS and increment are dealt with in 0050.. It is included as strikeout for comparison to our latest draft of the rules.