Applicability determination for sources in attainment areas causing or

contributing to NAAQS violation (a) The requirements in 40 CFR 51.165(b) regarding a source located in an attainment or unclassifiable area but causing or contributing to a NAAQS violation are hereby incorporated by reference as they exist on December 20, 2010. (b) Sources of VOC located outside a designated ozone nonattainment area will be presumed to have no significant impact on the designated nonattainment area. If ambient monitoring indicates 11 that the area of source location is in fact nonattainment, then the source may be granted its permit since the area has not yet been designated nonattainment. (c) Sources locating in an attainment area but impacting on a nonattainment area above the significant levels listed in OAC 252:100-8-52(a) are exempted from the condition of OAC 252:100-8-54(4)(A). (d) The determination whether a source or modification will cause or contribute to a violation of an applicable national ambient air quality standard for sulfur dioxide, particulate matter or carbon monoxide will be made on a case-by-case basis as of the proposed new source's start-up date by an atmospheric simulation model. For sources of nitrogen oxides the model can be used for an initial determination assuming all the nitric oxide emitted is oxidized to nitrogen dioxide by the time the plume reaches ground level, and the initial concentration estimates will be adjusted if adequate data are available to account for the expected oxidation rate. (e) The determination as to whether a source would cause or contribute to a violation of applicable national ambient air quality standards will be made on a case-by-case basis as of the new source's start-up date. Therefore, if a designated nonattainment area is projected to be attainment as part of the state implementation plan control strategy by the new source start-up date, offsets would not be required if the new source would not cause a new violation.