Ill. Admin. Code tit. 35, § 204.860
a) The requirements of Sections 204.810, 204.820, 204.830, 204.840, 204.850, 204.1100, 204.1110, 204.1120, 204.1130, 204.1140, 204.1200, and 204.1400 do not apply to a particular major stationary source or major modification, if:
2) The source or modification would be a major stationary source or major modification only if fugitive emissions, to the extent quantifiable, are considered in calculating the potential to emit of the stationary source or modification and the source does not belong to any of the following categories:
3) The source is a portable stationary source that has previously received a permit under 40 CFR 52.21 or this Part and:
c) The requirements of Sections 204.1110, 204.1130, and 204.1140 shall not apply to a major stationary source or major modification with respect to a particular pollutant if the allowable emissions of that pollutant from the source, or the net emissions increase of that pollutant from the modification: