Section 212.124  Exceptions

a)         Sections 212.122 and 212.123 will not apply to emissions of water or water vapor from an emission unit.

b)         An emission unit that has obtained an adjusted opacity standard in compliance with Section 212.126 will be subject to that standard rather than the limitations of Section 212.122 or 212.123.

c)         Compliance with the particulate regulations of this Part will constitute a defense.

1)         For all emission units that are not subject to Chapters 111 or 112 of the CAA and Sections 212.201, 212.202, 212.203 or 212.204 but are subject to Sections 212.122 or 212.123: the opacity limitations of Sections 212.122 and 212.123 will not apply if it is shown that the emission unit was, at the time of emission, in compliance with the applicable particulate emissions limitations of Subparts D through T.

2)         For all emission units that are not subject to Chapters 111 or 112 of the CAA but are subject to Sections 212.201, 212.202, 212.203 or 212.204:

A)        An exceedance of the limitations of Section 212.122 or 212.123 will constitute a violation of the applicable particulate limitations of Subparts D through T.  It will be a defense to a violation of the applicable particulate limitations if, during a subsequent performance test conducted within a reasonable time not to exceed 60 days, under the same operating conditions for the unit and the control devices, and in accordance with Method 5, 40 CFR 60, incorporated by reference in Section 212.113, the owner or operator shows that the emission unit is in compliance with the particulate emission limitations.

B)        It will be a defense to an exceedance of the opacity limit if, during a subsequent performance test conducted within a reasonable time not to exceed 60 days, under the same operating conditions of the emission unit and the control devices, and in accordance with Method 5, 40 CFR part 60, Appendix A, incorporated by reference in Section 212.113, the owner or operator shows that the emission unit is in compliance with the allowable particulate emissions limitation while, simultaneously, having visible emissions equal to or greater than the opacity exceedance as originally observed.

(Source:  Amended at 47 Ill. Reg. 12107, effective July 25, 2023)